Question: Select the bird below.

Choices:
- ocean sunfish
- water buffalo
- penguin
- common toad

Birds have feathers, two wings, and a beak.
Birds are warm-blooded. Warm-blooded animals can control their body temperature.
A bald eagle is an example of a bird.

natural science

Identify mammals, birds, fish, reptiles, and amphibians

Birds, mammals, fish, reptiles, and amphibians are groups of animals. Scientists sort animals into each group based on traits they have in common. This process is called classification.
Classification helps scientists learn about how animals live. Classification also helps scientists compare similar animals.

Solution:
A penguin is a bird. It has feathers, two wings, and a beak.
Penguins live near water. Penguins cannot fly! They use their wings to swim.
A water buffalo is a mammal. It has hair and feeds its young milk.
Water buffaloes live in Asia. Some people raise water buffaloes for their milk.
A common toad is an amphibian. It has moist skin and begins its life in water.
Toads do not have teeth! They swallow their food whole.
An ocean sunfish is a fish. It lives underwater. It has fins, not limbs.
Ocean sunfish have a flat body and wide fins. They sometimes swim to the ocean's surface to rest in the sun.


Question: Which of the following could Bruce's test show?

Choices:
- which side of the roof got more sun over one day
- how many solar panels could fit on each side of the roof
- the amount of sunlight the roof would get throughout the year

People can use the engineering-design process to develop solutions to problems. One step in the process is testing if a potential solution meets the requirements of the design.
The passage below describes how the engineering-design process was used to test a solution to a problem. Read the passage. Then answer the question below.

Bruce was installing solar panels on the roof of a client's house. The panels had to provide enough electricity to power the house year-round. Bruce needed to decide how many panels to install and which side of the roof to install them on. If he put the panels on the side that got the most sun, then he could use fewer panels, and the client would save money. Bruce installed sunlight sensors on both sides of the roof. Then, he measured the amount of sunlight the sensors on each side of the roof recorded over one sunny summer day.
Figure: installing solar panels on a roof.

natural science

Evaluate tests of engineering-design solutions

People can use the engineering-design process to develop solutions to problems. One step in the process is testing if a potential solution meets the requirements of the design. How can you determine what a test can show? You need to figure out what was tested and what was measured.
Imagine an engineer needs to design a bridge for a windy location. She wants to make sure the bridge will not move too much in high wind. So, she builds a smaller prototype, or model, of a bridge. Then, she exposes the prototype to high winds and measures how much the bridge moves.
First, identify what was tested. A test can examine one design, or it may compare multiple prototypes to each other. In the test described above, the engineer tested a prototype of a bridge in high wind.
Then, identify what the test measured. One of the criteria for the bridge was that it not move too much in high winds. The test measured how much the prototype bridge moved.
Tests can show how well one or more designs meet the criteria. The test described above can show whether the bridge would move too much in high winds.


Question: Which solution has a higher concentration of purple particles?

Choices:
- neither; their concentrations are the same
- Solution B
- Solution A

The diagram below is a model of two solutions. Each purple ball represents one particle of solute.

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent.
The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent.
concentration = particles of solute / volume of solvent

Solution:
In Solution A and Solution B, the purple particles represent the solute. To figure out which solution has a higher concentration of purple particles, look at both the number of purple particles and the volume of the solvent in each container.
Use the concentration formula to find the number of purple particles per milliliter.
Solution B has more purple particles per milliliter. So, Solution B has a higher concentration of purple particles.


Question: What is the name of the colony shown?

Choices:
- Maine
- Connecticut
- Delaware
- Pennsylvania

social science

Solution: The colony is Delaware.


Question: Based on the arrows, which of the following organisms is a producer?

Choices:
- lichen
- barren-ground caribou

Below is a food web from a tundra ecosystem in Nunavut, a territory in Northern Canada.
A food web models how the matter eaten by organisms moves through an ecosystem. The arrows in a food web represent how matter moves between organisms in an ecosystem.

natural science

A food web is a model.
A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food.
Arrows show how matter moves.
A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating.
An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web.
An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web.

Solution:
Producers do not eat other organisms. So, in a food web, producers do not have arrows pointing to them from other organisms.
The lichen does not have an arrow pointing to it. So, the lichen is a producer.
The barren-ground caribou has an arrow pointing to it from the lichen. So, the barren-ground caribou is a consumer, not a producer.


Question: What is the probability that a budgerigar parakeet produced by this cross will be heterozygous for the body feather color gene?

Choices:
- 4/4
- 2/4
- 3/4
- 1/4
- 0/4

In a group of budgerigar parakeets, some individuals have green body feathers and others have blue body feathers. In this group, the gene for the body feather color trait has two alleles. The allele for green body feathers (B) is dominant over the allele for blue body feathers (b).
This Punnett square shows a cross between two budgerigar parakeets.

natural science

Use Punnett squares to calculate probabilities of offspring types

Offspring genotypes: homozygous or heterozygous?
How do you determine whether an organism is homozygous or heterozygous for a gene? Look at the alleles in the organism's genotype for that gene.
An organism with two identical alleles for a gene is homozygous for that gene.
If both alleles are dominant, the organism is homozygous dominant for the gene.
If both alleles are recessive, the organism is homozygous recessive for the gene.
An organism with two different alleles for a gene is heterozygous for that gene.
In a Punnett square, each box represents a different outcome, or result. Each of the four outcomes is equally likely to happen. Each box represents one way the parents' alleles can combine to form an offspring's genotype.
Because there are four boxes in the Punnett square, there are four possible outcomes.
An event is a set of one or more outcomes. The probability of an event is a measure of how likely the event is to happen. This probability is a number between 0 and 1, and it can be written as a fraction:
probability of an event = number of ways the event can happen / number of equally likely outcomes
You can use a Punnett square to calculate the probability that a cross will produce certain offspring. For example, the Punnett square below has two boxes with the genotype Ff. It has one box with the genotype FF and one box with the genotype ff. This means there are two ways the parents' alleles can combine to form Ff. There is one way they can combine to form FF and one way they can combine to form ff.
 | F | f
F | FF | Ff
f | Ff | ff
Consider an event in which this cross produces an offspring with the genotype ff. The probability of this event is given by the following fraction:
number of ways the event can happen / number of equally likely outcomes = number of boxes with the genotype ff / total number of boxes = 1 / 4


Question: What is the capital of Idaho?

Choices:
- Oklahoma City
- Boise
- Baton Rouge
- Nampa

social science

Solution: Boise is the capital of Idaho.


Question: What is the capital of New Hampshire?

Choices:
- Montgomery
- Concord
- Manchester
- Jackson

social science

Identify state capitals of the Northeast

Solution: Concord is the capital of New Hampshire.


Question: Identify the question that Maya's experiment can best answer.

Choices:
- Do radish plants grown under bright light have more leaves than radish plants grown under dim light?
- Do radishes grown under bright light get bigger than radishes grown under dim light?

The passage below describes an experiment. Read the passage and then follow the instructions below.

Maya planted 20 radish plants in a greenhouse, putting each plant in its own pot. She placed ten of the pots under bright light and the other ten pots under dim light. Maya watered all the plants twice a day. After two months, she pulled the radish plants from the ground, threw away the leafy green tops, and measured the sizes of the radishes. She compared the sizes of the radishes grown under bright light to the sizes of the radishes grown under dim light.
Figure: a radish plant in soil.

natural science

Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment.
Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured.
First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested.
Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured.
Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height.
Examples of questions that this experiment can answer include:
Does soil type affect the height of daffodil plants?
Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil?
Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?


Question: Which solution has a higher concentration of yellow particles?

Choices:
- Solution A
- neither; their concentrations are the same
- Solution B

The diagram below is a model of two solutions. Each yellow ball represents one particle of solute.

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent.
The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent.
concentration = particles of solute / volume of solvent

Solution:
In Solution A and Solution B, the yellow particles represent the solute. To figure out which solution has a higher concentration of yellow particles, look at both the number of yellow particles and the volume of the solvent in each container.
Use the concentration formula to find the number of yellow particles per milliliter.
Solution A and Solution B have the same number of yellow particles per milliliter. So, their concentrations are the same.


Question: Which month has the highest average precipitation in Santiago?

Choices:
- August
- June
- March

Use the graph to answer the question below.

natural science

Scientists record climate data from places around the world. Precipitation, or rain and snow, is one type of climate data.
A bar graph can be used to show the average amount of precipitation each month. Months with taller bars have more precipitation on average.

Solution:
To describe the average precipitation trends in Santiago, look at the graph.
Choice "Mar" is incorrect.
Choice "Jun" is incorrect.
Choice "Aug" is incorrect.
June has an average monthly precipitation of about 80 millimeters. This is higher than in any other month. So, June has the highest average precipitation.


Question: Which continent is highlighted?

Choices:
- Asia
- Antarctica
- South America
- Africa

social science

A continent is one of the seven largest areas of land on earth.

Solution: This continent is Africa.


Question: Does Rhizophora mangle have cells that have a nucleus?

Choices:
- yes
- no

This organism is Rhizophora mangle. It is a member of the plant kingdom.
Rhizophora mangle is commonly called a red mangrove. Red mangrove trees grow in or near water. They have strong roots that help prop, or hold, them up. These roots are also aerial, which means that they can grow above the ground. So, the red mangrove roots are called aerial prop roots.

natural science

Describe, classify, and compare kingdoms

In the past, scientists classified living organisms into two groups: plants and animals. Over the past 300 years, scientists have discovered many more types of organisms. Today, many scientists classify organisms into six broad groups, called kingdoms.
Organisms in each kingdom have specific traits. The table below shows some traits used to describe each kingdom.
 | Bacteria | Archaea | Protists | Fungi | Animals | Plants
How many cells do they have? | one | one | one or many | one or many | many | many
Do their cells have a nucleus? | no | no | yes | yes | yes | yes
Can their cells make food? | some species can | some species can | some species can | no | no | yes

Solution: Rhizophora mangle is a plant. Plant cells have a nucleus.


Question: Compare the average kinetic energies of the particles in each sample. Which sample has the higher temperature?

Choices:
- sample B
- sample A
- neither; the samples have the same temperature

The diagrams below show two pure samples of gas in identical closed, rigid containers. Each colored ball represents one gas particle. Both samples have the same number of particles.

natural science

Identify how particle motion affects temperature and pressure

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance.
The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy.

Solution:
Each particle in sample B has more mass than each particle in sample A. The particles in sample B also have a higher average speed than the particles in sample A. So, the particles in sample B have a higher average kinetic energy than the particles in sample A.
Because the particles in sample B have the higher average kinetic energy, sample B must have the higher temperature.


Question: Which country is highlighted?

Choices:
- New Zealand
- Palau
- the Marshall Islands
- Papua New Guinea

social science

Identify and select countries of Oceania

Solution: This country is New Zealand.


Question: Which state is highlighted?

Choices:
- Michigan
- Minnesota
- North Dakota
- Iowa

social science

Solution: This state is Michigan.


Question: Is Hevea brasiliensis made up of many cells?

Choices:
- yes
- no

This organism is Hevea brasiliensis. It is a member of the plant kingdom.
Hevea brasiliensis is commonly called a rubber tree. Rubber trees make a white liquid called latex. Rubber trees use latex for protection. Latex has a bad taste and can be poisonous to some animals. So, the latex helps to stop animals from eating the rubber tree's leaves and branches.

natural science

Describe, classify, and compare kingdoms

In the past, scientists classified living organisms into two groups: plants and animals. Over the past 300 years, scientists have discovered many more types of organisms. Today, many scientists classify organisms into six broad groups, called kingdoms.
Organisms in each kingdom have specific traits. The table below shows some traits used to describe each kingdom.
 | Bacteria | Archaea | Protists | Fungi | Animals | Plants
How many cells do they have? | one | one | one or many | one or many | many | many
Do their cells have a nucleus? | no | no | yes | yes | yes | yes
Can their cells make food? | some species can | some species can | some species can | no | no | yes

Solution: Hevea brasiliensis is a plant. Plants are made up of many cells.


Question: Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

Choices:
- The magnitude of the magnetic force is greater in Pair 1.
- The magnitude of the magnetic force is the same in both pairs.
- The magnitude of the magnetic force is greater in Pair 2.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material.

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces.
The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other.
You can change the magnitude of a magnetic force between two magnets by changing the distance between them. The magnitude of the magnetic force is greater when there is a smaller distance between the magnets.

Solution:
Distance affects the magnitude of the magnetic force. When there is a smaller distance between magnets, the magnitude of the magnetic force between them is greater.
There is a smaller distance between the magnets in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is greater in Pair 2 than in Pair 1.


Question:
Is the following statement about our solar system true or false?
The smallest planet is made mainly of rock.

Choices:
- false
- true

Use the data to answer the question below.

natural science

Analyze data to compare properties of planets

A planet's volume tells you the size of the planet.
The primary composition of a planet is what the planet is made mainly of. In our solar system, planets are made mainly of rock, gas, or ice.
The volume of a planet is a very large quantity. Large quantities such as this are often written in scientific notation.
For example, the volume of Jupiter is 1,430,000,000,000,000 km^3. In scientific notation, Jupiter's volume is written as 1.43 x 10^15 km^3.
To compare two numbers written in scientific notation, compare their exponents. The bigger the exponent is, the bigger the number is. For example:
1.43 x 10^15 is larger than 1.43 x 10^12
If their exponents are equal, compare the first numbers. For example:
1.43 x 10^15 is larger than 1.25 x 10^15

Solution:
To decide which planet is the smallest, look at the volumes shown in the table and compare the exponents. Mercury's volume has an exponent of 10, which is the smallest out of all the planets.
Mercury is made mainly of rock. So, the smallest planet is made mainly of rock.


Question: Which type of relationship is formed when a hawk moth visits a petunia flower?

Choices:
- commensal
- mutualistic
- parasitic

Read the passage. Then answer the question.

Hawk moths visit many types of plants to find nectar, including petunias. Petunias produce nectar deep inside their flowers. To reach the nectar, a moth puts its long, tubular mouthpart, called a proboscis, inside a flower. While the moth drinks nectar, pollen from the flower sticks to the moth's head and proboscis.
Later, the moth visits another petunia flower to drink more nectar. When pollen on the moth's head and proboscis is transferred to the female part of the other flower, that flower is pollinated. After the moth pollinates the flower, the petunia is able to reproduce.
Figure: a hawk moth visiting a petunia flower.

natural science

When two organisms of different species interact in a way that affects one or both organisms, they form a symbiotic relationship. The word symbiosis comes from a Greek word that means living together. Scientists define types of symbiotic relationships based on how each organism is affected.
This table lists three common types of symbiotic relationships. It shows how each organism is affected in each type of symbiotic relationship.
Type of symbiotic relationship | Organism of one species... | Organism of the other species...
Commensal | benefits | is not significantly affected
Mutualistic | benefits | benefits
Parasitic | benefits | is harmed (but not usually killed)

Solution:
When a hawk moth visits a petunia flower, the moth drinks nectar. The moth uses the nectar to survive and grow. So, the moth benefits from its relationship with the petunia.
The petunia flower is pollinated when the moth visits it. After the petunia is pollinated, it is able to reproduce. So, the petunia also benefits from its relationship with the moth.
Since both the moth and the petunia benefit, a mutualistic relationship is formed when a hawk moth pollinates a petunia flower.


Question: What is the capital of Montana?

Choices:
- Boston
- Billings
- Bismarck
- Helena

social science

Solution: Helena is the capital of Montana.


Question: What is the capital of California?

Choices:
- San Francisco
- Sacramento
- Atlanta
- Carson City

social science

Solution: Sacramento is the capital of California.


Question: Which country is highlighted?

Choices:
- Saint Kitts and Nevis
- Haiti
- Barbados
- Saint Lucia

social science

Identify and select countries of the Caribbean

Solution: This country is Saint Lucia.


Question: Which material is these swim goggles made of?

Choices:
- rock
- rubber

natural science

A material is a type of matter. Wood, glass, metal, and plastic are common materials.
Some objects are made of just one material.
Most nails are made of metal.
Other objects are made of more than one material.
This hammer is made of metal and wood.

Solution:
Look at the picture of the swim goggles.
The swim goggles are made of two different materials. The lenses are plastic, and the straps are rubber.


Question: Select the true statement.

Choices:
- Genes affect traits.
- Eye color is an example of a gene.

Look at the image and read the text. Then, answer the question.
variation in the human eye color trait
All organisms inherit certain traits from their parents. Information about these inherited traits is found in genes. Genes are pieces of hereditary material that are passed from parents to offspring. An organism's genes affect its inherited traits.

natural science

Genes, proteins, and traits: understanding the genetic code

Solution:
Genes are passed down from parents to offspring.
When an organism reproduces, it passes copies of its genes to its offspring. This is how information about inherited traits is passed down.
All organisms have genes.
All organisms have genes that contain information about their inherited traits.
Eye color is an example of a gene.
An organism's eye color is affected by its genes. But eye color is not a gene. Eye color is a trait, which is an observable characteristic of an organism.
Genes affect traits.
Genes contain information about inherited traits.


Question: What is the capital of California?

Choices:
- Los Angeles
- Sacramento
- San Francisco
- Nampa

social science


Question: Which animal's mouth is also adapted to get insects out of burrows?

Choices:
- gorilla
- long-beaked echidna

Giant anteaters eat insects such as ants and termites. These insects often live in holes called burrows. The anteater's mouth is adapted to get insects out of burrows.
Figure: giant anteater.

natural science

Animal adaptations: beaks, mouths, and necks

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors.
The shape of an animal's mouth is one example of an adaptation. Animals' mouths can be adapted in different ways. For example, a large mouth with sharp teeth might help an animal tear through meat. A long, thin mouth might help an animal catch insects that live in holes. Animals that eat similar food often have similar mouths.

Solution:
Look at the picture of the giant anteater.
A tube-shaped snout helps the giant anteater reach into a burrow. A long, sticky tongue helps it catch the insects.
Now look at each animal. Figure out which animal has a similar adaptation.
The long-beaked echidna has a tube-shaped snout and a long, sticky tongue. Its mouth is adapted to eat insects that live inside burrows.
The mountain gorilla has a wide snout. Its mouth is not adapted to get insects out of burrows. The mountain gorilla uses its mouth to eat leaves and fruit.


Question: Will these magnets attract or repel each other?

Choices:
- attract
- repel

Two magnets are placed as shown.

Hint: Magnets that attract pull together. Magnets that repel push apart.

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart.
Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles, called north and south.
Here are some examples of magnets. The north pole of each magnet is marked N, and the south pole is marked S.
If different poles are closest to each other, the magnets attract. The magnets in the pair below attract.
If the same poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

Solution:
Will these magnets attract or repel? To find out, look at which poles are closest to each other.
The south pole of one magnet is closest to the north pole of the other magnet. Poles that are different attract. So, these magnets will attract each other.


Question: Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

Choices:
- The magnitude of the magnetic force is smaller in Pair 2.
- The magnitude of the magnetic force is smaller in Pair 1.
- The magnitude of the magnetic force is the same in both pairs.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material, but some of them are different sizes.

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces.
The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other.
You can change the magnitude of a magnetic force between two magnets by using magnets of different sizes. The magnitude of the magnetic force is smaller when the magnets are smaller.

Solution:
The magnets in Pair 1 attract. The magnets in Pair 2 repel. But whether the magnets attract or repel affects only the direction of the magnetic force. It does not affect the magnitude of the magnetic force.
Magnet sizes affect the magnitude of the magnetic force. Imagine magnets that are the same shape and made of the same material. The smaller the magnets, the smaller the magnitude of the magnetic force between them.
Magnet A is the same size in both pairs. But Magnet B is smaller in Pair 1 than in Pair 2. So, the magnitude of the magnetic force is smaller in Pair 1 than in Pair 2.


Question: What is the capital of Maryland?

Choices:
- Boston
- Plymouth
- Baltimore
- Annapolis

social science

Identify state capitals of the Northeast

Solution: Annapolis is the capital of Maryland.


Question: Select the organism in the same species as the Panamanian golden frog.

Choices:
- Atelopus zeteki
- Hyla japonica
- Bufo guttatus

This organism is a Panamanian golden frog. Its scientific name is Atelopus zeteki.

natural science

Use scientific names to classify organisms

Scientists use scientific names to identify organisms. Scientific names are made of two words.
The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits.
A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus.
Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus.
Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur.

Solution:
A Panamanian golden frog's scientific name is Atelopus zeteki.
Hyla japonica does not have the same scientific name as a Panamanian golden frog. So, Atelopus zeteki and Hyla japonica are not in the same species.
Bufo guttatus does not have the same scientific name as a Panamanian golden frog. So, Atelopus zeteki and Bufo guttatus are not in the same species.
Atelopus zeteki has the same scientific name as a Panamanian golden frog. So, these organisms are in the same species.


Question: Select the mammal below.

Choices:
- hammerhead shark
- red-headed poison frog
- water buffalo
- woodpecker

Mammals have hair or fur and feed their young milk.
Mammals are warm-blooded. Warm-blooded animals can control their body temperature.
A sea otter is an example of a mammal.

natural science

Identify mammals, birds, fish, reptiles, and amphibians

Birds, mammals, fish, reptiles, and amphibians are groups of animals. Scientists sort animals into each group based on traits they have in common. This process is called classification.
Classification helps scientists learn about how animals live. Classification also helps scientists compare similar animals.

Solution:
A red-headed poison frog is an amphibian. It has moist skin and begins its life in water.
Poison dart frogs come in many bright colors. Their bright color warns other animals that these frogs are poisonous.
A woodpecker is a bird. It has feathers, two wings, and a beak.
Woodpeckers have strong beaks. They use their beaks to drill into wood to hunt for food.
A water buffalo is a mammal. It has hair and feeds its young milk.
Water buffaloes live in Asia. Some people raise water buffaloes for their milk.
A hammerhead shark is a fish. It lives underwater. It has fins, not limbs.
Hammerhead sharks get their names from the shape of their heads. They have a wide, flat head and a small mouth.


Question: Which country is highlighted?

Choices:
- Haiti
- the Dominican Republic
- Cuba
- The Bahamas

social science

Identify and select countries of the Caribbean

Solution: This country is The Bahamas.


Question: Which ocean is highlighted?

Choices:
- the Pacific Ocean
- the Southern Ocean
- the Indian Ocean
- the Atlantic Ocean

social science

Oceans are huge bodies of salt water. The world has five oceans. All of the oceans are connected, making one world ocean.

Solution: This is the Indian Ocean.


Question: Identify the question that Jayce's experiment can best answer.

Choices:
- Do steel nails rust in fewer days when submerged in a large volume of liquid compared to a small volume?
- Do steel nails take fewer days to rust in water compared to vinegar?

The passage below describes an experiment. Read the passage and then follow the instructions below.

Jayce put one two-inch steel nail into each of six test tubes. He added water to three of the test tubes and vinegar to the other three. In each test tube, he completely covered the nail with the same volume of liquid. Jayce checked the nails for rust at the same time every day. He recorded how many days it took each nail to become completely covered in rust. Then, he compared the number of days it took nails to rust in water to the number of days it took nails to rust in vinegar.
Figure: a new steel nail on a pile of rusty nails.

natural science

Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment.
Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured.
First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested.
Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured.
Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height.
Examples of questions that this experiment can answer include:
Does soil type affect the height of daffodil plants?
Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil?
Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?


Question: Which of these states is farthest south?

Choices:
- California
- Rhode Island
- New York
- Washington

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west.
A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction.
The north arrow points to the North Pole. On most maps, north is at the top of the map.

Solution: To find the answer, look at the compass rose. Look at which way the south arrow is pointing. California is farthest south.


Question: Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

Choices:
- The magnitude of the magnetic force is the same in both pairs.
- The magnitude of the magnetic force is greater in Pair 2.
- The magnitude of the magnetic force is greater in Pair 1.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material.

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces.
The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other.
You can change the magnitude of a magnetic force between two magnets by changing the distance between them. The magnitude of the magnetic force is greater when there is a smaller distance between the magnets.


Question: Which statement best describes the average monthly precipitation in New Orleans?

Choices:
- October is the wettest month.
- The wettest months of the year are June, July, and August.
- June, July, and August are the driest months of the year.

Use the graph to answer the question below.

natural science

Scientists record climate data from places around the world. Precipitation, or rain and snow, is one type of climate data. Scientists collect data over many years. They can use this data to calculate the average precipitation for each month. The average precipitation can be used to describe the climate of a location.
A bar graph can be used to show the average amount of precipitation each month. Months with taller bars have more precipitation on average.

Solution:
To describe the average precipitation trends in New Orleans, look at the graph.
Choice "Jun" is incorrect.
Choice "Jul" is incorrect.
Choice "Aug" is incorrect.
Choice "Oct" is incorrect.
Choice "The wettest months of the year are June, July, and August." is incorrect.
On average, more precipitation falls during June, July, and August than during other months of the year. So, June, July, and August are the wettest months.
Choice "June, July, and August are the driest months of the year." is incorrect.
On average, slightly more precipitation falls during June, July, and August than during the other months of the year. So, June, July, and August are not the driest months.
Choice "October is the wettest month." is incorrect.
Every other month has a higher average precipitation than October. So, October is the driest, not the wettest, month.


Question: Which property do these three objects have in common?

Choices:
- rough
- salty
- yellow

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it.
Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification.

Solution:
Look at each object.
For each object, decide if it has that property.
Yellow is a color.
This color is yellow. The potato chips are yellow, but the ocean water is not.
A rough object feels scratchy when you touch it. The cracker and the potato chips are rough, but the ocean water is not.
Potato chips have a salty taste. All three objects are salty.
The property that all three objects have in common is salty.


Question: What is the name of the colony shown?

Choices:
- Georgia
- North Carolina
- Tennessee
- Pennsylvania

social science

Solution: The colony is Pennsylvania.


Question: Which country is highlighted?

Choices:
- Dominica
- Antigua and Barbuda
- Barbados
- Saint Kitts and Nevis

social science

Identify and select countries of the Caribbean

Solution: This country is Antigua and Barbuda.


Question: Which solution has a higher concentration of yellow particles?

Choices:
- Solution B
- neither; their concentrations are the same
- Solution A

The diagram below is a model of two solutions. Each yellow ball represents one particle of solute.

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent.
The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent.
concentration = particles of solute / volume of solvent

Solution:
In Solution A and Solution B, the yellow particles represent the solute. To figure out which solution has a higher concentration of yellow particles, look at both the number of yellow particles and the volume of the solvent in each container.
Use the concentration formula to find the number of yellow particles per milliliter.
Solution A and Solution B have the same number of yellow particles per milliliter. So, their concentrations are the same.


Question: Look at the models of molecules below. Select the elementary substance.

Choices:
- bromomethane
- trichlorofluoromethane
- tetraphosphorus

natural science

Identify elementary substances and compounds using models

There are more than 100 different chemical elements, or types of atoms. Chemical elements make up all of the substances around you.
A substance may be composed of one chemical element or multiple chemical elements. Substances that are composed of only one chemical element are elementary substances. Substances that are composed of multiple chemical elements bonded together are compounds.
Every chemical element is represented by its own atomic symbol. An atomic symbol may consist of one capital letter, or it may consist of a capital letter followed by a lowercase letter. For example, the atomic symbol for the chemical element boron is B, and the atomic symbol for the chemical element chlorine is Cl.
Scientists use different types of models to represent substances whose atoms are bonded in different ways. One type of model is a ball-and-stick model. The ball-and-stick model below represents a molecule of the compound boron trichloride.
In a ball-and-stick model, the balls represent atoms, and the sticks represent bonds. Notice that the balls in the model above are not all the same color. Each color represents a different chemical element. The legend shows the color and the atomic symbol for each chemical element in the substance.


Question: Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

Choices:
- The magnitude of the magnetic force is smaller in Pair 2.
- The magnitude of the magnetic force is smaller in Pair 1.
- The magnitude of the magnetic force is the same in both pairs.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material, but some of them are different shapes.

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces.
The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other.

Solution:
The magnets in Pair 2 attract. The magnets in Pair 1 repel. But whether the magnets attract or repel affects only the direction of the magnetic force. It does not affect the magnitude of the magnetic force.
Both magnet sizes and distance affect the magnitude of the magnetic force. The sizes of the magnets in Pair 1 are the same as in Pair 2. The distance between the magnets is also the same.
So, the magnitude of the magnetic force is the same in both pairs.


Question: Which property do these four objects have in common?

Choices:
- translucent
- flexible
- sweet

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it.
Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification.

Solution:
Look at each object.
For each object, decide if it has that property.
A flexible object can be folded or bent without breaking easily. The jello is flexible, but the wet ice cube is not.
Sugar has a sweet taste. The jello is sweet, but the wet ice cube and the ocean water are not.
A translucent object lets light through. But you cannot see clearly through a translucent object. All four objects are translucent.
The property that all four objects have in common is translucent.


Question: Which better describes the Peary Land ecosystem?

Choices:
- It has short, cold summers. It also has many trees and shrubs.
- It has long, cold winters. It also has mostly small plants.

Figure: Peary Land.
Peary Land is a tundra ecosystem in northern Greenland.

natural science

An environment includes all of the biotic, or living, and abiotic, or nonliving, things in an area. An ecosystem is created by the relationships that form among the biotic and abiotic parts of an environment.
There are many different types of terrestrial, or land-based, ecosystems. Here are some ways in which terrestrial ecosystems can differ from each other:
the pattern of weather, or climate
the type of soil
the organisms that live there

Solution: A tundra is a type of ecosystem. Tundras have the following features: long, cold winters and short, cold summers, soil that is frozen year-round, and mostly small plants. So, Peary Land has long, cold winters. It also has mostly small plants.


Question: What is the capital of Georgia?

Choices:
- Athens
- Tallahassee
- Savannah
- Atlanta

social science

Identify state capitals of the Southeast

Solution: Atlanta is the capital of Georgia.


Question: Select the organism in the same genus as the sand cat.

Choices:
- Felis margarita
- Lynx canadensis
- Lynx rufus

This organism is a sand cat. Its scientific name is Felis margarita.

natural science

Use scientific names to classify organisms

Scientists use scientific names to identify organisms. Scientific names are made of two words.
The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits.
A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus.
Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus.
Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur.

Solution:
A sand cat's scientific name is Felis margarita. The first word of its scientific name is Felis.
Lynx canadensis is in the genus Lynx. The first word of its scientific name is Lynx. So, Lynx canadensis and Felis margarita are not in the same genus.
Lynx rufus is in the genus Lynx. The first word of its scientific name is Lynx. So, Lynx rufus and Felis margarita are not in the same genus.
This organism and the sand cat are in the same genus and the same species! Both organisms have the same scientific name, Felis margarita.


Question: Which solution has a higher concentration of yellow particles?

Choices:
- Solution B
- Solution A
- neither; their concentrations are the same

The diagram below is a model of two solutions. Each yellow ball represents one particle of solute.

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent.
The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent.
concentration = particles of solute / volume of solvent

Solution:
In Solution A and Solution B, the yellow particles represent the solute. To figure out which solution has a higher concentration of yellow particles, look at both the number of yellow particles and the volume of the solvent in each container.
Use the concentration formula to find the number of yellow particles per milliliter.
Solution B has more yellow particles per milliliter. So, Solution B has a higher concentration of yellow particles.


Question: What is the direction of this pull?

Choices:
- away from the magnet
- toward the magnet

A horseshoe magnet attracts paper clips with a magnetic force. This magnetic force pulls the paper clips upward so they do not fall.

natural science

A force is a push or a pull that one object applies to another. Every force has a direction.
The direction of a push is away from the object that is pushing.
The direction of a pull is toward the object that is pulling.

Solution: The magnet pulls the paper clips upward. The direction of the pull is toward the magnet.


Question: Which of these states is farthest west?

Choices:
- Illinois
- Georgia
- Maryland
- Ohio

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west.
A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction.
The north arrow points to the North Pole. On most maps, north is at the top of the map.

Solution: To find the answer, look at the compass rose. Look at which way the west arrow is pointing. Illinois is farthest west.


Question: What can Lamar and Jackson trade to each get what they want?

Choices:
- Jackson can trade his almonds for Lamar's tomatoes.
- Jackson can trade his broccoli for Lamar's oranges.
- Lamar can trade his tomatoes for Jackson's carrots.
- Lamar can trade his tomatoes for Jackson's broccoli.

Trade happens when people agree to exchange goods and services. People give up something to get something else. Sometimes people barter, or directly exchange one good or service for another.
Lamar and Jackson open their lunch boxes in the school cafeteria. Neither Lamar nor Jackson got everything that they wanted. The table below shows which items they each wanted:

Look at the images of their lunches. Then answer the question below.
Lamar's lunch Jackson's lunch

social science

Solution:
Look at the table and images.
Lamar wants broccoli. Jackson wants tomatoes. They can trade tomatoes for broccoli to both get what they want. Trading other things would not help both people get more items they want.


Question: Which of these cities is marked on the map?

Choices:
- Los Angeles
- Chicago
- San Francisco
- Denver

social science

Solution: The city is San Francisco, California. Los Angeles, Denver, and Chicago are marked with gray circles on the map below.


Question: Which better describes the Belize Barrier Reef ecosystem?

Choices:
- It has salty water. It also has many different types of organisms.
- It has water with not much salt. It also has many different types of organisms.

Figure: Belize Barrier Reef.
The Belize Barrier Reef is a tropical coral reef ecosystem near the coast of Belize.

natural science

An ecosystem is formed when living and nonliving things interact in an environment. There are many types of ecosystems. Here are some ways in which ecosystems can differ from each other:
the pattern of weather, or climate
the type of soil or water
the organisms that live there

Solution: A tropical coral reef is a type of ecosystem. Tropical coral reefs have the following features: shallow, salty water, bright sunlight, and many different types of organisms. So, the Belize Barrier Reef has salty water. It also has many different types of organisms.


Question: Which property do these three objects have in common?

Choices:
- fragile
- sticky
- colorful

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it.
Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification.

Solution:
Look at each object.
For each object, decide if it has that property.
A colorful object has one or more bright colors. All three objects are colorful.
A sticky object can attach or stick to other things. None of the objects are sticky.
A fragile object will break into pieces if you drop it. The socks and the hot air balloon are not fragile.
The property that all three objects have in common is colorful.


Question: Which type of force from the older brother moves the car forward?

Choices:
- pull
- push

A boy and his younger brother play with their toy car in the snow. The older brother applies a force to the back of the car to move it forward.

natural science

A force is a push or a pull that one object applies to a second object.
The direction of a push is away from the object that is pushing.
The direction of a pull is toward the object that is pulling.

Solution: The older brother applies a force to the back of the car. This force moves the car forward. The direction of this force is away from the older brother. This force is a push.


Question: Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

Choices:
- The magnitude of the magnetic force is the same in both pairs.
- The magnitude of the magnetic force is greater in Pair 2.
- The magnitude of the magnetic force is greater in Pair 1.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material, but some of them are different sizes and shapes.

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces.
The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other.
You can change the magnitude of a magnetic force between two magnets by using magnets of different sizes. The magnitude of the magnetic force is greater when the magnets are larger.

Solution:
The magnets in Pair 2 attract. The magnets in Pair 1 repel. But whether the magnets attract or repel affects only the direction of the magnetic force. It does not affect the magnitude of the magnetic force.
Magnet sizes affect the magnitude of the magnetic force. Imagine magnets that are the same shape and made of the same material. The larger the magnets, the greater the magnitude of the magnetic force between them.
Magnet A is the same size in both pairs. But Magnet B is larger in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is greater in Pair 2 than in Pair 1.


Question: Which of these states is farthest west?

Choices:
- Colorado
- California
- Texas
- North Dakota

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west.
A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction.
The north arrow points to the North Pole. On most maps, north is at the top of the map.

Solution: To find the answer, look at the compass rose. Look at which way the west arrow is pointing. California is farthest west.


Question: Select the organism in the same genus as the gray heron.

Choices:
- Lissotriton helveticus
- Ardea cinerea
- Hyla cinerea

This organism is a gray heron. Its scientific name is Ardea cinerea.

natural science

Use scientific names to classify organisms

Scientists use scientific names to identify organisms. Scientific names are made of two words.
The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits.
A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus.
Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus.
Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur.

Solution:
A gray heron's scientific name is Ardea cinerea. The first word of its scientific name is Ardea.
Lissotriton helveticus is in the genus Lissotriton. The first word of its scientific name is Lissotriton. So, Lissotriton helveticus and Ardea cinerea are not in the same genus.
This organism and the gray heron are in the same genus and the same species! Both organisms have the same scientific name, Ardea cinerea.
Hyla cinerea and Ardea cinerea are not in the same genus.
These organisms are not in the same genus, but part of their scientific names is the same. Hyla cinerea and Ardea cinerea have the same species name within their genus, cinerea. But the first words of their scientific names are different. Hyla cinerea is in the genus Hyla, and Ardea cinerea is in the genus Ardea.


Question: Which air temperature was measured within the outlined area shown?

Choices:
- -22°C
- -1°C
- 2°C

The map below shows air temperatures in the lower atmosphere on October 28, 2016. The outlined area shows an air mass that influenced weather in Asia on that day.
Look at the map. Then, answer the question below.
Data source: United States National Oceanic and Atmospheric Administration/Earth System Research Laboratory, Physical Sciences Division

natural science

To study air masses, scientists can use maps that show conditions within Earth's atmosphere. For example, the map below uses color to show air temperatures.
The map's legend tells you the temperature that each color represents. Colors on the left in the legend represent lower temperatures than colors on the right. For example, areas on the map that are the darkest shade of blue have a temperature from -25°C up to -20°C. Areas that are the next darkest shade of blue have a temperature from -20°C up to -15°C.

Solution:
Look at the colors shown within the outlined area. Then, use the legend to determine which air temperatures those colors represent.
10°C.
-22°C is within this range.
-1°C and 2°C are outside of this range.


Question: Which i in column 3?

Choices:
- the library
- the restaurant
- the police department
- the grocery store

social science

A grid is made up of lines of squares. They are organized in rows and columns. A grid can help you use a map.
A row is a line of squares that goes from side to side. Rows are marked with letters.
A column is a line of squares that goes up and down. Columns are marked with numbers.

Solution: The grocery store is in column 3.


Question:
Complete the statement.
Phosphine is ().

Choices:
- a compound
- an elementary substance

The model below represents a molecule of phosphine. Phosphine is a poisonous gas that some farmers use to kill insects.

natural science

Classify elementary substances and compounds using models

There are more than 100 different chemical elements, or types of atoms. Chemical elements make up all of the substances around you.
A substance may be composed of one chemical element or multiple chemical elements. Substances that are composed of only one chemical element are elementary substances. Substances that are composed of multiple chemical elements bonded together are compounds.
Every chemical element is represented by its own atomic symbol. An atomic symbol may consist of one capital letter, or it may consist of a capital letter followed by a lowercase letter. For example, the atomic symbol for the chemical element boron is B, and the atomic symbol for the chemical element chlorine is Cl.
Scientists use different types of models to represent substances whose atoms are bonded in different ways. One type of model is a ball-and-stick model. The ball-and-stick model below represents a molecule of the compound boron trichloride.
In a ball-and-stick model, the balls represent atoms, and the sticks represent bonds. Notice that the balls in the model above are not all the same color. Each color represents a different chemical element. The legend shows the color and the atomic symbol for each chemical element in the substance.

Solution:
Use the model to determine whether phosphine is an elementary substance or a compound.
Step 1: Interpret the model.
.
Use the legend to determine the chemical element represented by each color. The colors and atomic symbols from the legend are shown in the table below. The table also includes the names of the chemical elements represented in the model.
You can see from the model that a molecule of phosphine is composed of three hydrogen atoms and one phosphorus atom bonded together.
Step 2: Determine whether the substance is an elementary substance or a compound.
You know from Step 1 that phosphine is composed of two chemical elements: hydrogen and phosphorus. Since phosphine is composed of multiple chemical elements bonded together, phosphine is a compound.


Question: Which statement describes the Sonoran Desert ecosystem?

Choices:
- It has only a few types of organisms.
- It has warm, wet summers.
- It has a small amount of rain.

Figure: Sonoran Desert.
The Sonoran Desert is a hot desert ecosystem in the southwestern United States and northwestern Mexico. This desert is home to wild saguaro cactus, which can grow over 70 feet tall.

natural science

An environment includes all of the biotic, or living, and abiotic, or nonliving, things in an area. An ecosystem is created by the relationships that form among the biotic and abiotic parts of an environment.
There are many different types of terrestrial, or land-based, ecosystems. Here are some ways in which terrestrial ecosystems can differ from each other:
the pattern of weather, or climate
the type of soil
the organisms that live there

Solution: A hot desert is a type of ecosystem. Hot deserts have the following features: a small amount of rain, dry, thin soil, and many different types of organisms. So, the following statement describes the Sonoran Desert ecosystem: a small amount of rain, dry, thin soil, and many different types of organisms. It has a small amount of rain. The following statements do not describe the Sonoran Desert: a small amount of rain, dry, thin soil, and many different types of organisms. It has warm, wet summers. It has only a few types of organisms.


Question: Is a bowling ball a solid, a liquid, or a gas?

Choices:
- a liquid
- a solid
- a gas

natural science

Classify matter as solid, liquid, or gas

Solid, liquid, and gas are states of matter. Matter is anything that takes up space. Matter can come in different states, or forms.
When matter is a solid, it has a definite volume and a definite shape. So, a solid has a size and shape of its own.
Some solids can be easily folded, bent, or broken. A piece of paper is a solid. Also, some solids are very small. A grain of sand is a solid.
When matter is a liquid, it has a definite volume but not a definite shape. So, a liquid has a size of its own, but it does not have a shape of its own. Think about pouring juice from a bottle into a cup. The juice still takes up the same amount of space, but it takes the shape of the bottle.
Some liquids do not pour as easily as others. Honey and milk are both liquids. But pouring honey takes more time than pouring milk.
When matter is a gas, it does not have a definite volume or a definite shape. A gas expands, or gets bigger, until it completely fills a space. A gas can also get smaller if it is squeezed into a smaller space.
Many gases are invisible. Air is a gas.

Solution:
A bowling ball is a solid. A solid has a size and shape of its own.
A bowling ball can knock down bowling pins. But after it hits the pins, the bowling ball still has a size and shape of its own.


Question: What is the capital of Montana?

Choices:
- Billings
- Honolulu
- Cincinnati
- Helena

social science

Solution: Helena is the capital of Montana.


Question: What is the name of the colony shown?

Choices:
- New Hampshire
- Kentucky
- Georgia
- Rhode Island

social science

Solution: The colony is Rhode Island.


Question: What can Samir and Derek trade to each get what they want?

Choices:
- Samir can trade his tomatoes for Derek's carrots.
- Derek can trade his broccoli for Samir's oranges.
- Derek can trade his almonds for Samir's tomatoes.
- Samir can trade his tomatoes for Derek's broccoli.

Trade happens when people agree to exchange goods and services. People give up something to get something else. Sometimes people barter, or directly exchange one good or service for another.
Samir and Derek open their lunch boxes in the school cafeteria. Neither Samir nor Derek got everything that they wanted. The table below shows which items they each wanted:

Look at the images of their lunches. Then answer the question below.
Samir's lunch Derek's lunch

social science

Solution:
Look at the table and images.
Samir wants broccoli. Derek wants tomatoes. They can trade tomatoes for broccoli to both get what they want. Trading other things would not help both people get more items they want.


Question: What is the capital of Idaho?

Choices:
- Pierre
- Nampa
- Santa Fe
- Boise

social science

Solution: Boise is the capital of Idaho.


Question: What is the capital of Alabama?

Choices:
- Norfolk
- Salem
- Birmingham
- Montgomery

social science

Identify state capitals of the Southeast

Solution: Montgomery is the capital of Alabama.


Question: Which trait did Curculioides adompha have? Select the trait you can observe on the fossil.

Choices:
- red eyes
- eight legs

This picture shows a fossil of an animal called Curculioides adompha. This fossil is more than 300,000,000 years old.

natural science

The way an organism looks or acts is called a trait. Scientists use fossils to learn more about the traits of ancient organisms.
Fossils can preserve the remains of body parts and activities. A fossil of a body part, such as a tail or a wing, can tell you what an organism looked like. A fossil of an organism's activities, such as a burrow or a footprint, can tell you about the organism's behavior.
Here are three examples of fossils and the traits that you can observe from them:
This is a fossil of an animal. This fossil tells you that the animal had a spiral-shaped shell.
This is a fossil of a plant. This fossil tells you that the plant had small leaves arranged in a branched pattern.
This is a fossil of an animal's footprint. This fossil tells you that the animal could walk on land.
An organism's fossil may not show all of the organism's traits. This is because most body parts are destroyed during fossil formation. When an organism's body turns into a fossil, only a few body parts are usually preserved.


Question: What is the name of the colony shown?

Choices:
- Maine
- Pennsylvania
- Delaware
- Massachusetts

social science

Solution: The colony is Pennsylvania.


Question: Does this passage describe the weather or the climate?

Choices:
- weather
- climate

Figure: Las Vegas.
Las Vegas is in the desert. On average, Las Vegas has almost 300 clear, sunny days each year!
Hint: Weather is what the atmosphere is like at a certain place and time. Climate is the pattern of weather in a certain place.

natural science

The atmosphere is the layer of air that surrounds Earth. Both weather and climate tell you about the atmosphere.
Weather is what the atmosphere is like at a certain place and time. Weather can change quickly. For example, the temperature outside your house might get higher throughout the day.
Climate is the pattern of weather in a certain place. For example, summer temperatures in New York are usually higher than winter temperatures.

Solution:
Read the passage carefully.
Las Vegas is in the desert. On average, Las Vegas has almost 300 clear, sunny days each year!
The underlined part of the passage tells you about the usual pattern of cloud cover in Las Vegas. This passage does not describe what the weather is like on a particular day. So, this passage describes the climate.


Question: What is the capital of Washington?

Choices:
- Seattle
- Sacramento
- Salt Lake City
- Olympia

social science

Solution: Olympia is the capital of Washington.


Question: Compare the average kinetic energies of the particles in each sample. Which sample has the higher temperature?

Choices:
- neither; the samples have the same temperature
- sample B
- sample A

The diagrams below show two pure samples of gas in identical closed, rigid containers. Each colored ball represents one gas particle. Both samples have the same number of particles.

natural science

Identify how particle motion affects temperature and pressure

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance.
The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy.

Solution:
The particles in both samples have the same average speed, but each particle in sample B has more mass than each particle in sample A. So, the particles in sample B have a higher average kinetic energy than the particles in sample A.
Because the particles in sample B have the higher average kinetic energy, sample B must have the higher temperature.


Question: What is the capital of Michigan?

Choices:
- Detroit
- Oklahoma City
- Jefferson City
- Lansing

social science

Solution: Lansing is the capital of Michigan.


Question: What is the name of the colony shown?

Choices:
- Florida
- Virginia
- Vermont
- West Virginia

social science

Solution:
The colony is Virginia.
The Virginia Colony included land that would later become part of the state of West Virginia. West Virginia was never its own colony.


Question: What is the capital of Ohio?

Choices:
- Cleveland
- Cincinnati
- Concord
- Columbus

social science

Solution: Columbus is the capital of Ohio.


Question: What is the capital of Colorado?

Choices:
- Pittsburgh
- Denver
- Seattle
- Helena

social science

Solution: Denver is the capital of Colorado.


Question: In which region did the Republican candidate do the best?

Choices:
- the Northwest
- the South
- the West

By the 1850s, slavery was a major issue in presidential elections. In 1856, the antislavery Republican Party competed in its first presidential election. Use the election map to answer the question below.

social science

Antebellum Period: slavery and politics part II


Question: What is the capital of Arkansas?

Choices:
- Columbia
- Austin
- Fayetteville
- Little Rock

social science

Identify state capitals of the Southeast

Solution: Little Rock is the capital of Arkansas.


Question: Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

Choices:
- The magnitude of the magnetic force is greater in Pair 1.
- The magnitude of the magnetic force is the same in both pairs.
- The magnitude of the magnetic force is greater in Pair 2.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material, but some of them are different sizes.

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces.
The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other.
You can change the magnitude of a magnetic force between two magnets by using magnets of different sizes. The magnitude of the magnetic force is greater when the magnets are larger.

Solution:
The magnets in Pair 1 attract. The magnets in Pair 2 repel. But whether the magnets attract or repel affects only the direction of the magnetic force. It does not affect the magnitude of the magnetic force.
Magnet sizes affect the magnitude of the magnetic force. Imagine magnets that are the same shape and made of the same material. The larger the magnets, the greater the magnitude of the magnetic force between them.
Magnet A is the same size in both pairs. But Magnet B is larger in Pair 1 than in Pair 2. So, the magnitude of the magnetic force is greater in Pair 1 than in Pair 2.


Question: What can Jenny and Zoe trade to each get what they want?

Choices:
- Zoe can trade her almonds for Jenny's tomatoes.
- Jenny can trade her tomatoes for Zoe's carrots.
- Zoe can trade her broccoli for Jenny's oranges.
- Jenny can trade her tomatoes for Zoe's broccoli.

Trade happens when people agree to exchange goods and services. People give up something to get something else. Sometimes people barter, or directly exchange one good or service for another.
Jenny and Zoe open their lunch boxes in the school cafeteria. Neither Jenny nor Zoe got everything that they wanted. The table below shows which items they each wanted:

Look at the images of their lunches. Then answer the question below.
Jenny's lunch Zoe's lunch

social science

Solution:
Look at the table and images.
Jenny wants broccoli. Zoe wants tomatoes. They can trade tomatoes for broccoli to both get what they want. Trading other things would not help both people get more items they want.


Question: Which solution has a higher concentration of green particles?

Choices:
- Solution A
- Solution B
- neither; their concentrations are the same

The diagram below is a model of two solutions. Each green ball represents one particle of solute.

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent.
The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent.
concentration = particles of solute / volume of solvent

Solution:
In Solution A and Solution B, the green particles represent the solute. To figure out which solution has a higher concentration of green particles, look at both the number of green particles and the volume of the solvent in each container.
Use the concentration formula to find the number of green particles per milliliter.
Solution B has more green particles per milliliter. So, Solution B has a higher concentration of green particles.


Question: What is the capital of North Dakota?

Choices:
- Pierre
- Juneau
- Bismarck
- Jefferson City

social science

Solution: Bismarck is the capital of North Dakota.


Question: Which country is highlighted?

Choices:
- Saint Kitts and Nevis
- Antigua and Barbuda
- Jamaica
- Saint Lucia

social science

Identify and select countries of the Caribbean

Solution: This country is Saint Kitts and Nevis.


Question: What is the capital of South Dakota?

Choices:
- Pierre
- Sioux Falls
- Madison
- Springfield

social science

Solution: Pierre is the capital of South Dakota.


Question: Which state is highlighted?

Choices:
- Montana
- Oregon
- California
- Washington

social science

Solution: This state is Oregon.


Question: Which ocean is highlighted?

Choices:
- the Pacific Ocean
- the Arctic Ocean
- the Southern Ocean
- the Atlantic Ocean

social science

Oceans are huge bodies of salt water. The world has five oceans. All of the oceans are connected, making one world ocean.

Solution: This is the Atlantic Ocean.


Question: Look at the picture. Which word best describes the sound this thunderstorm makes?

Choices:
- purring
- booming
- squeaking

language science

Choose the sensory details that match the picture

When you write, you can use sensory details. These sense words help your reader understand what something looks, sounds, tastes, smells, or feels like.
Sensory Category | Description
Sight | These are words like bright, clean, and purple. A reader can imagine looking at these details.
Sound | These are words like hissing, buzzing, and ringing. A reader can imagine hearing these details.
Taste | These are words like juicy, sweet, and burnt. A reader can imagine tasting these details.
Smell | These are words like fruity, sweet, and stinky. A reader can imagine smelling these details.
Touch | These are words like fuzzy, wet, and soft. A reader can imagine feeling these details.
Many sense words can describe more than one sense. For example, soft can describe a touch or a sound. And sweet can describe a taste or a smell.

Solution:
Look at the picture.
The word booming describes the sound this thunderstorm makes.
Purring and squeaking can also describe sounds. But they do not describe the sounds this thunderstorm makes.


Question: Which continent is highlighted?

Choices:
- Australia
- South America
- North America
- Europe

social science

A continent is one of the major land masses on the earth. Most people say there are seven continents.

Solution: This continent is South America.


Question: Which continent is highlighted?

Choices:
- Europe
- Asia
- Africa
- South America

social science

A continent is one of the seven largest areas of land on earth.

Solution: This continent is Europe.


Question: Which of the following organisms is the primary consumer in this food web?

Choices:
- Arctic fox
- rough-legged hawk
- mushroom

Below is a food web from a tundra ecosystem in Nunavut, a territory in Northern Canada.
A food web models how the matter eaten by organisms moves through an ecosystem. The arrows in a food web represent how matter moves between organisms in an ecosystem.

natural science

A food web is a model.
A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food.
Arrows show how matter moves.
A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating.
An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web.
An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web.

Solution:
Primary consumers eat producers. So, in a food web, primary consumers have arrows pointing to them from producers.
The mushroom has arrows pointing to it from the barren-ground caribou and the grizzly bear. Neither the barren-ground caribou nor the grizzly bear is a producer, so the earthworm is not a primary consumer.
The Arctic fox has an arrow pointing to it from the bilberry. The bilberry is a producer, so the Arctic fox is a primary consumer.
The barren-ground caribou has an arrow pointing to it from the lichen. The lichen is a producer, so the barren-ground caribou is a primary consumer.
The rough-legged hawk has an arrow pointing to it from the parasitic jaeger. The parasitic jaeger is not a producer, so the rough-legged hawk is not a primary consumer.


Question: Is diamond a mineral?

Choices:
- no
- yes

Diamond has the following properties:
not made by living things
fixed crystal structure
found in nature
solid
made of carbon, which is a pure substance

natural science

Properties are used to identify different substances. Minerals have the following properties:
It is a solid.
It is formed in nature.
It is not made by organisms.
It is a pure substance.
It has a fixed crystal structure.
If a substance has all five of these properties, then it is a mineral.
Look closely at the last three properties:
A mineral is not made by organisms.
Organisms make their own body parts. For example, snails and clams make their shells. Because they are made by organisms, body parts cannot be minerals.
Humans are organisms too. So, substances that humans make by hand or in factories cannot be minerals.
A mineral is a pure substance.
A pure substance is made of only one type of matter. All minerals are pure substances.
A mineral has a fixed crystal structure.
The crystal structure of a substance tells you how the atoms or molecules in the substance are arranged. Different types of minerals have different crystal structures, but all minerals have a fixed crystal structure. This means that the atoms or molecules in different pieces of the same type of mineral are always arranged the same way.

Solution: Diamond has all the properties of a mineral. So, diamond is a mineral.


Question: Select the fish below.

Choices:
- clownfish
- American alligator

Fish live underwater. They have fins, not limbs. A manta ray is an example of a fish.

natural science

Identify mammals, birds, fish, reptiles, and amphibians

Birds, mammals, fish, reptiles, and amphibians are groups of animals. The animals in each group have traits in common.
Scientists sort animals into groups based on traits they have in common. This process is called classification.

Solution:
A clownfish is a fish. It lives underwater. It has fins, not limbs.
An American alligator is a reptile. It has scaly, waterproof skin.


Question: What is the probability that a cockatiel produced by this cross will have bright orange cheeks?

Choices:
- 2/4
- 4/4
- 0/4
- 1/4
- 3/4

In a group of cockatiels, some individuals have bright orange cheeks and others have pale orange cheeks. In this group, the gene for the cheek color trait has two alleles. The allele for bright orange cheeks (R) is dominant over the allele for pale orange cheeks (r).
This Punnett square shows a cross between two cockatiels.

natural science

Use Punnett squares to calculate probabilities of offspring types

Offspring phenotypes: dominant or recessive?
How do you determine an organism's phenotype for a trait? Look at the combination of alleles in the organism's genotype for the gene that affects that trait. Some alleles have types called dominant and recessive. These two types can cause different versions of the trait to appear as the organism's phenotype.
If an organism's genotype has at least one dominant allele for a gene, the organism's phenotype will be the dominant allele's version of the gene's trait.
If an organism's genotype has only recessive alleles for a gene, the organism's phenotype will be the recessive allele's version of the gene's trait.
In a Punnett square, each box represents a different outcome, or result. Each of the four outcomes is equally likely to happen. Each box represents one way the parents' alleles can combine to form an offspring's genotype. Because there are four boxes in the Punnett square, there are four possible outcomes.
An event is a set of one or more outcomes. The probability of an event is a measure of how likely the event is to happen. This probability is a number between 0 and 1, and it can be written as a fraction:
probability of an event = number of ways the event can happen / number of equally likely outcomes
You can use a Punnett square to calculate the probability that a cross will produce certain offspring. For example, the Punnett square below has two boxes with the genotype Ff. It has one box with the genotype FF and one box with the genotype ff. This means there are two ways the parents' alleles can combine to form Ff. There is one way they can combine to form FF and one way they can combine to form ff.
 | F | f
F | FF | Ff
f | Ff | ff
Consider an event in which this cross produces an offspring with the genotype ff. The probability of this event is given by the following fraction:
number of ways the event can happen / number of equally likely outcomes = number of boxes with the genotype ff / total number of boxes = 1 / 4.


Question: Which bird's beak is also adapted to crack hard seeds?

Choices:
- common swift
- hawfinch

Evening grosbeaks eat small, hard seeds. The shape of the 's beak is adapted to crack open small, hard seeds.
Figure: evening grosbeak.

natural science

Animal adaptations: beaks, mouths, and necks

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors.
The shape of a bird's beak is one example of an adaptation. Birds' beaks can be adapted in different ways. For example, a sharp hooked beak might help a bird tear through meat easily. A short, thick beak might help a bird break through a seed's hard shell. Birds that eat similar food often have similar beaks.

Solution:
Look at the picture of the evening grosbeak.
The evening grosbeak has a short, thick beak. Its beak is adapted to crack hard seeds. The evening grosbeak uses its short, thick beak to press down on a seed and crack open its hard shell.
Now look at each bird. Figure out which bird has a similar adaptation.
The hawfinch has a short, thick beak. Its beak is adapted to crack hard seeds.
The common swift has a short, thin beak. Its beak is not adapted to crack hard seeds. The common swift uses its beak to eat insects and other small invertebrates.


Question: Which property do these three objects have in common?

Choices:
- shiny
- bouncy
- bumpy

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it.
Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification.

Solution:
Look at each object.
For each object, decide if it has that property.
A shiny object reflects a lot of light. You can usually see your reflection in a shiny object. The gold nugget is shiny, but the log is not.
A bumpy object is covered in lumps and bumps. All three objects are bumpy.
A bouncy object will bounce back from the floor if you drop it. The gold nugget is not bouncy.
The property that all three objects have in common is bumpy.


Question: Identify the question that Ronald's experiment can best answer.

Choices:
- Do more bacteria grow in liquid with cinnamon than in liquid without cinnamon?
- Does temperature affect how much bacteria can grow in liquid?

The passage below describes an experiment. Read the passage and then follow the instructions below.

Ronald mixed bacteria into a nutrient-rich liquid where the bacteria could grow. He poured four ounces of the mixture into each of ten glass flasks. In five of the ten flasks, he also added one teaspoon of cinnamon. He allowed the bacteria in the flasks to grow overnight in a 37°C room. Then, Ronald used a microscope to count the number of bacteria in a small sample from each flask. He compared the amount of bacteria in the liquid with cinnamon to the amount of bacteria in the liquid without cinnamon.
Figure: flasks of liquid for growing bacteria.

natural science

Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment.
Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured.
First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested.
Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured.
Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height.
Examples of questions that this experiment can answer include:
Does soil type affect the height of daffodil plants?
Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil?
Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?


Question: Identify the question that Diane's experiment can best answer.

Choices:
- Do radishes grown under bright light get bigger than radishes grown under dim light?
- Do radish plants grown under bright light have more leaves than radish plants grown under dim light?

The passage below describes an experiment. Read the passage and then follow the instructions below.

Diane planted 20 radish plants in a greenhouse, putting each plant in its own pot. She placed ten of the pots under bright light and the other ten pots under dim light. Diane watered all the plants twice a day. After two months, she pulled the radish plants from the ground, threw away the leafy green tops, and measured the sizes of the radishes. She compared the sizes of the radishes grown under bright light to the sizes of the radishes grown under dim light.
Figure: a radish plant in soil.

natural science

Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment.
Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured.
First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested.
Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured.
Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height.
Examples of questions that this experiment can answer include:
Does soil type affect the height of daffodil plants?
Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil?
Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?


Question: Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

Choices:
- The magnitude of the magnetic force is greater in Pair 1.
- The magnitude of the magnetic force is greater in Pair 2.
- The magnitude of the magnetic force is the same in both pairs.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material, but some of them are different sizes.

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces.
The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other.
You can change the magnitude of a magnetic force between two magnets by using magnets of different sizes. The magnitude of the magnetic force is greater when the magnets are larger.

Solution:
The magnets in Pair 1 attract. The magnets in Pair 2 repel. But whether the magnets attract or repel affects only the direction of the magnetic force. It does not affect the magnitude of the magnetic force.
Magnet sizes affect the magnitude of the magnetic force. Imagine magnets that are the same shape and made of the same material. The larger the magnets, the greater the magnitude of the magnetic force between them.
Magnet A is the same size in both pairs. But Magnet B is larger in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is greater in Pair 2 than in Pair 1.


Question: Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

Choices:
- The magnitude of the magnetic force is smaller in Pair 1.
- The magnitude of the magnetic force is smaller in Pair 2.
- The magnitude of the magnetic force is the same in both pairs.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material, but some of them are different shapes.

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces.
The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other.
You can change the magnitude of a magnetic force between two magnets by changing the distance between them. The magnitude of the magnetic force is smaller when there is a greater distance between the magnets.

Solution:
Distance affects the magnitude of the magnetic force. When there is a greater distance between magnets, the magnitude of the magnetic force between them is smaller.
There is a greater distance between the magnets in Pair 1 than in Pair 2. So, the magnitude of the magnetic force is smaller in Pair 1 than in Pair 2.


Question: When might a giant tortoise sleep for weeks at a time?

Choices:
- when there is not much water
- when the tortoise is growing quickly
- when it is cold outside

Read the text about giant tortoises.
The Galápagos Islands in the Pacific Ocean are home to the giant tortoise. These tortoises are massive, weighing nearly five hundred pounds. However, giant tortoises do not use much energy.
They often rest for up to sixteen hours a day. And when there is little water, giant tortoises might sleep for weeks at a time. This helps them save energy. Giant tortoises can live up to a year without food or water if they have to!
Life has not always been easy for giant tortoises, though. When people first arrived at the Galápagos Islands hundreds of years ago, they took many of the tortoises away. And some people hunted the tortoises for food and oil. Few tortoises are left on the island today. Luckily, many groups of people are now working to keep these giant animals safe. Hopefully, giant tortoises can roam the islands for many years to come.

language science

Solution:
Look at the text in bold below. It tells you when a giant Galápagos tortoise might sleep for weeks at a time.
The Galápagos Islands in the Pacific Ocean are home to the giant tortoise. These tortoises are massive, weighing nearly five hundred pounds. However, giant tortoises do not use much energy. They often rest for up to sixteen hours a day. And when there is little water, giant tortoises might sleep for weeks at a time. This helps them save energy. Giant tortoises can live up to a year without food or water if they have to!


Question: What is the capital of Oregon?

Choices:
- Boston
- Portland
- Salem
- Jefferson City

social science

Solution: Salem is the capital of Oregon.


Question: Which country is highlighted?

Choices:
- Dominica
- Saint Kitts and Nevis
- Jamaica
- the Dominican Republic

social science

Identify and select countries of the Caribbean

Solution:
This country is the Dominican Republic.
Why does the Dominican Republic share its island with another country?
The Dominican Republic and Haiti share the island of Hispaniola. It is home to the earliest European settlements in the Americas. Christopher Columbus founded the first European settlement on the island in 1492 during his first voyage across the Atlantic.
Though many people lived on the island before Columbus's arrival, European countries quickly began to colonize the island. Eventually France and Spain both established colonies. The Spanish colony eventually became the country of the Dominican Republic, and the French colony eventually became the country of Haiti. Today, people in the two countries speak different languages and have many cultural differences.