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

Choices:
- flexible
- transparent
- opaque

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.

Solution:
Look at each object.
For each object, decide if it has that property.
An opaque object does not let light through. None of the objects are opaque.
A flexible object can be folded or bent without breaking easily. The glass and the glass flask are not flexible.
You can see clearly through a transparent object. All three objects are transparent.
The property that all three objects have in common is transparent.


Question: Which is the main persuasive appeal used in this ad?

Choices:
- pathos (emotion)
- ethos (character)
- logos (reason)

language science

Identify appeals to ethos, pathos, and logos in advertisements

The purpose of an advertisement is to persuade people to do something. To accomplish this purpose, advertisements use three types of persuasive strategies, or appeals:
Appeals to ethos, or character, show that the writer or speaker is trustworthy or is an authority on a subject. An ad that appeals to ethos might do one of the following:
say that a brand has been trusted for many years
note that a brand is recommended by a respected organization or celebrity
include a quote from a "real person" who shares the audience's values
Appeals to logos, or reason, use logic and specific evidence. An ad that appeals to logos might do one of the following:
use graphs or charts to display information
mention the results of scientific studies
explain the science behind a product or service
Appeals to pathos, or emotion, use feelings rather than facts to persuade the audience. An ad that appeals to pathos might do one of the following:
trigger a fear, such as the fear of embarrassment
appeal to a desire, such as the desire to appear attractive
link the product to a positive feeling, such as adventure, love, or luxury

Solution: The ad appeals to ethos, or character. It includes an endorsement (seal of approval) from a respected organization.


Question: What is the name of the colony shown?

Choices:
- Maine
- Rhode Island
- New York
- Virginia

social science

Solution: The colony is Rhode Island.


Question: Select the mammal below.

Choices:
- gray wolf
- keel-billed toucan

Mammals have hair or fur and feed their young milk. 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. 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 keel-billed toucan is a bird. It has feathers, two wings, and a beak.
Toucans have large beaks. A toucan's beak can be half as long as its body.
A gray wolf is a mammal. It has fur and feeds its young milk.
Wolves often live in family groups. A wolf mother, father, and their children travel together.


Question: What is the name of the colony shown?

Choices:
- New Jersey
- New York
- Maryland
- Delaware

social science

Solution:
The colony is New York.
During the colonial era, New Hampshire and New York both claimed the territory that would later become the state of Vermont. Vermont was never its own colony.


Question: Will these magnets attract or repel each other?

Choices:
- repel
- attract

natural science

Magnets can pull or push on other magnets without touching them. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes are called magnetic forces.
Magnetic forces are strongest at the magnets' poles, or ends. Every magnet has two poles: a north pole (N) and a south pole (S).
Here are some examples of magnets. Their poles are shown in different colors and labeled.
Whether a magnet attracts or repels other magnets depends on the positions of its poles.
If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract.
If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

Solution:
To predict if these magnets will attract or repel, look at which poles are closest to each other.
The north pole of one magnet is closest to the north pole of the other magnet. Like poles repel. So, these magnets will repel each other.


Question: Will these magnets attract or repel each other?

Choices:
- attract
- repel

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: north and south.
Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S.
If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract.
If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel.


Question: Which bird's beak is also adapted to crack large, hard nuts?

Choices:
- bald ibis
- scarlet macaw

s eat large seeds and nuts. The shape of the 's beak is adapted to crack open large, hard nuts.
Figure: Alexandrine parakeet.

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 Alexandrine parakeet.
The Alexandrine parakeet has a thick hooked beak. Its beak is adapted to crack large, hard nuts. The Alexandrine parakeet uses its thick beak to crack the shell of a nut by squeezing it. The hooked shape of the beak can help the bird hold the nut in place while cracking it.
Now look at each bird. Figure out which bird has a similar adaptation.
The scarlet macaw has a thick hooked beak. Its beak is adapted to crack large, hard nuts.
The bald ibis has a long curved beak. Its beak is not adapted to crack large, hard nuts.


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

Choices:
- if adding the blade guards made the drone fly poorly
- if the blade guards would break in a crash
- how much the drone weighed with the blade guards

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.

Helen was designing small aircraft called drones to pick up items from warehouse shelves. She knew that the drones' propeller blades would get damaged if they bumped into anything while flying through the warehouse. So, Helen wanted to add blade guards to protect the propeller blades. The guards had to be sturdy so they would not break in a crash. But she thought that if the guards weighed too much, the drones would not fly well.
So, Helen put guards made of lightweight metal on one drone. Then she observed how well the drone flew with the guards.
Figure: a drone without blade guards.

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

Choices:
- acetaldehyde
- hydrazine
- ozone

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 magnetic force is weaker in Pair 1.
- The magnetic force is weaker in Pair 2.
- The strength 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.

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 stronger the magnetic force between two magnets, the more strongly the magnets attract or repel each other.

Solution:
Distance affects the strength of the magnetic force. But the distance between the magnets in Pair 1 and in Pair 2 is the same.
So, the strength of the magnetic force is the same in both pairs.


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

Choices:
- The strength of the magnetic force is the same in both pairs.
- The magnetic force is weaker in Pair 2.
- The magnetic force is weaker 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 stronger the magnetic force between two magnets, the more strongly the magnets attract or repel each other.
You can change the strength of a magnetic force between two magnets by changing the distance between them. The magnetic force is weaker when the magnets are farther apart.

Solution:
Distance affects the strength of the magnetic force. When magnets are farther apart, the magnetic force between them is weaker.
The magnets in Pair 1 are farther apart than the magnets in Pair 2. So, the magnetic force is weaker in Pair 1 than in Pair 2.


Question: Which of the following could Marcy and Brenda's test show?

Choices:
- if a new batch of concrete was firm enough to use
- if the concrete from each batch took the same amount of time to dry

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.

Marcy and Brenda were making batches of concrete for a construction project. To make the concrete, they mixed together dry cement powder, gravel, and water. Then, they checked if each batch was firm enough using a test called a slump test.
They poured some of the fresh concrete into an upside-down metal cone. They left the concrete in the metal cone for 30 seconds. Then, they lifted the cone to see if the concrete stayed in a cone shape or if it collapsed. If the concrete in a batch collapsed, they would know the batch should not be used.
Figure: preparing a concrete slump test.

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: The United States has a federal system. Based on these definitions, which of these statements would most likely be made by a person who lives under a federal system?

Choices:
- My national government officials decide most issues that come up.
- I only pay attention to state politics since the national government has almost no power.
- Both my state and national government officials have power over important issues.

Think about the name of the United States of America. As the name shows, the country has both a united national government and a collection of state governments. In the following questions, you will learn about the relationship between the national government and state governments. You will also learn about how state and local governments work.
Many countries have both a national government and state governments. However, these countries divide power differently between the national and state governments. The table below describes three different systems for dividing power. Look at the table. Then answer the question below.

social science


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

Choices:
- Does the amount of water in a glass affect whether eggs sink or float in the water?
- Are eggs more likely to float in fresh water or salty water?

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

Lacey poured four ounces of water into each of six glasses. Lacey dissolved one tablespoon of salt in each of three glasses, and did not add salt to the other three. Then, Lacey placed an egg in one glass and observed if the egg floated. She removed the egg and dried it. She repeated the process with the other five glasses, recording each time if the egg floated. Lacey repeated this test with two more eggs and counted the number of times the eggs floated in fresh water compared to salty water.
Figure: an egg floating in a glass of salty water.

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: 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 north pole of one magnet is closest to the north pole of the other magnet. Poles that are the same repel. So, these magnets will repel each other.


Question: Which country is highlighted?

Choices:
- Jamaica
- Grenada
- Cuba
- Haiti

social science

Identify and select countries of the Caribbean

Solution: This country is Jamaica.


Question: What is the name of the colony shown?

Choices:
- Connecticut
- Pennsylvania
- New Hampshire
- Vermont

social science

Solution:
The colony is New Hampshire.
During the colonial era, New Hampshire and New York both claimed the territory that would later become the state of Vermont. Vermont was never its own colony.


Question: During this time, thermal energy was transferred from () to ().

Choices:
- the surroundings . . . each vial
- each vial . . . the surroundings

Scientists in a laboratory were working with insulin, a protein often used to treat diabetes. They left two identical vials of insulin in different places. This table shows how the temperature of each vial changed over 15minutes.

natural science

A change in an object's temperature indicates a change in the object's thermal energy:
An increase in temperature shows that the object's thermal energy increased. So, thermal energy was transferred into the object from its surroundings.
A decrease in temperature shows that the object's thermal energy decreased. So, thermal energy was transferred out of the object to its surroundings.

Solution: The temperature of each vial increased, which means that the thermal energy of each vial increased. So, thermal energy was transferred from the surroundings to each vial.


Question: What is the capital of Pennsylvania?

Choices:
- Hartford
- Harrisburg
- Nashville
- Pittsburgh

social science

Identify state capitals of the Northeast

Solution: Harrisburg is the capital of Pennsylvania.


Question: Will these magnets attract or repel each other?

Choices:
- repel
- attract

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.


Question: What can Arianna and Clarence trade to each get what they want?

Choices:
- Arianna can trade her tomatoes for Clarence's sandwich.
- Arianna can trade her tomatoes for Clarence's broccoli.
- Clarence can trade his broccoli for Arianna's oranges.
- Clarence can trade his almonds for Arianna's tomatoes.

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.
Arianna and Clarence open their lunch boxes in the school cafeteria. Both of them could be happier with their lunches. Arianna wanted broccoli in her lunch and Clarence was hoping for tomatoes. Look at the images of their lunches. Then answer the question below.

social science

Solution:
Arianna wanted broccoli in her lunch and Clarence was hoping for tomatoes. Look at the labeled part of the images.
Arianna has tomatoes. Clarence has broccoli. They can trade tomatoes for broccoli to both be happier. Trading other things would not help either person get more items they want.


Question: Is the water in a glass a solid, a liquid, or a gas?

Choices:
- a solid
- a gas
- a liquid

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:
The water in a glass is a liquid. A liquid takes the shape of any container it is in.
If you pour water from a glass into a different container, the water will take the shape of that container. But the water will still take up the same amount of space.


Question: What is the capital of New York?

Choices:
- Montpelier
- New York City
- Louisville
- Albany

social science

Identify state capitals of the Northeast

Solution: Albany is the capital of New York.


Question: Is Bertholletia excelsa made up of one cell?

Choices:
- yes
- no

This organism is Bertholletia excelsa. It is a member of the plant kingdom.
Bertholletia excelsa is commonly called a Brazil nut tree. Brazil nut trees have a tall, thin trunk. Branches grow near the top of the tree. A Brazil nut tree can live for over 500 years!

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: Bertholletia excelsa is a plant. Plants are made up of many cells.


Question:
Is the following statement about our solar system true or false?
Three-quarters of the planets are larger than Earth.

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 planets are larger than Earth, look at the volumes of the other planets and compare the exponents to the exponent of Earth's volume. Earth's volume is 1.08 x 10^12 km^3. Earth's volume is the only volume with an exponent of 12.
The volumes of Jupiter, Saturn, Uranus, and Neptune have exponents greater than 12, so these four planets are larger than Earth. There are eight planets total. So, one-half of the planets are larger than Earth.


Question: Which animal's skin is better adapted as a warning sign to ward off predators?

Choices:
- lichen katydid
- opalescent nudibranch

Flamboyant cuttlefish are poisonous animals with brightly colored skin. The bright colors serve as a warning sign that the animal is poisonous. The 's skin is adapted to ward off predators.
Figure: flamboyant cuttlefish.

natural science

Animal adaptations: skins and body coverings

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors.
The color, texture, and covering of an animal's skin are examples of adaptations. Animals' skins can be adapted in different ways. For example, skin with thick fur might help an animal stay warm. Skin with sharp spines might help an animal defend itself against predators.

Solution:
Look at the picture of the flamboyant cuttlefish.
The flamboyant cuttlefish has a poisonous body with brightly colored skin. Its skin is adapted to ward off predators. The bright colors serve as a warning sign that the flamboyant cuttlefish is poisonous.
Now look at each animal. Figure out which animal has a similar adaptation.
The opalescent nudibranch has stinging cells in its brightly colored skin. Its skin is adapted to ward off predators.
The lichen katydid has green and white patches on its body. Its skin is not adapted to be a warning sign that wards off predators.


Question: Which three months have over 200millimeters of precipitation in Singapore?

Choices:
- November, December, and January
- August, September, and October
- May, June, and July

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 Singapore, look at the graph.
Choice "Jan" is incorrect.
Choice "May" is incorrect.
Choice "Jun" is incorrect.
Choice "Jul" is incorrect.
Choice "Aug" is incorrect.
Choice "Sep" is incorrect.
Choice "Oct" is incorrect.
Choice "Nov" is incorrect.
Choice "Dec" is incorrect.
November, December, and January each have over 200 millimeters of precipitation.


Question: Is scoria a mineral or a rock?

Choices:
- rock
- mineral

Scoria has the following properties:
no fixed crystal structure
has many small holes
not a pure substance
found in nature
solid
not made by organisms

natural science

Minerals are the building blocks of rocks. A rock can be made of one or more minerals.
Minerals and rocks have the following properties:
Property | Mineral | Rock
It is a solid. | Yes | Yes
It is formed in nature. | Yes | Yes
It is not made by organisms. | Yes | Yes
It is a pure substance. | Yes | No
It has a fixed crystal structure. | Yes | No
You can use these properties to tell whether a substance is a mineral, a rock, or neither.
Look closely at the last three properties:
Minerals and rocks are 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 or rocks.
Humans are organisms too. So, substances that humans make by hand or in factories are not minerals or rocks.
A mineral is a pure substance, but a rock is not.
A pure substance is made of only one type of matter.  Minerals are pure substances, but rocks are not. Instead, all rocks are mixtures.
A mineral has a fixed crystal structure, but a rock does not.
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 and molecules in different pieces of the same type of mineral are always arranged the same way.
However, rocks do not have a fixed crystal structure. So, the arrangement of atoms or molecules in different pieces of the same type of rock may be different!

Solution: The properties of scoria match the properties of a rock. So, scoria is a rock.


Question: What is the capital of Ohio?

Choices:
- Cincinnati
- Columbus
- Frankfort
- Cleveland

social science

Solution: Columbus is the capital of Ohio.


Question: Which animal's legs are also adapted for wading?

Choices:
- common kingfisher
- painted stork

Gray herons live near marshes, rivers, and lakes. They eat frogs and fish that live in shallow water. Gray herons hunt their prey by walking through water, or wading.
The 's legs are adapted for wading. They are lightweight and keep the bird's body above the water.
Figure: gray heron.

natural science

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors.
Arms, legs, flippers, and wings are different types of limbs. The type of limbs an animal has is an example of an adaptation. Animals' limbs can be adapted in different ways. For example, long legs might help an animal run fast. Flippers might help an animal swim. Wings might help an animal fly.

Solution:
Look at the picture of the gray heron.
Long legs help the gray heron keep its body above the surface of the water while wading. Thin legs are easier to move through the water.
Now look at each animal. Figure out which animal has a similar adaptation.
The painted stork has long, thin legs. Its legs are adapted for wading.
The common kingfisher has short legs. Its legs are not adapted for wading. The common kingfisher uses its legs to walk and perch.


Question: What is the probability that a Syrian hamster produced by this cross will have long fur?

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

In a group of Syrian hamsters, some individuals have short fur and others have long fur. In this group, the gene for the fur length trait has two alleles. The allele for short fur (F) is dominant over the allele for long fur (f).
This Punnett square shows a cross between two Syrian hamsters.

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 of these states is farthest south?

Choices:
- Kansas
- Connecticut
- Ohio
- South 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 south arrow is pointing. Kansas is farthest south.


Question: Will these magnets attract or repel each other?

Choices:
- attract
- repel

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: north and south.
Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S.
If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract.
If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

Solution:
To predict if these magnets will attract or repel, look at which poles are closest to each other.
The north pole of one magnet is closest to the south pole of the other magnet. Opposite poles attract. So, these magnets will attract each other.


Question: Which country is highlighted?

Choices:
- Saint Vincent and the Grenadines
- Saint Lucia
- Grenada
- Haiti

social science

Identify and select countries of the Caribbean

Solution: This country is Saint Vincent and the Grenadines.


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

Choices:
- if the new turbine could turn easily
- whether the new turbine could produce 10% more electricity
- how much the new turbine would weigh

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.

Wind turbines use wind power to produce electricity. Rose was a materials engineer who designed wind turbines. She wanted to design a new turbine that would produce 10% more electricity than older wind turbines. She thought that a turbine made from lightweight material would turn more easily and produce more electricity. So, Rose created a computer model of a turbine made from lightweight material. Then she used the model to calculate how much more electricity the new turbine could produce compared to the older turbines.
Figure: studying a wind turbine computer model.

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 country is highlighted?

Choices:
- Solomon Islands
- Papua New Guinea
- New Zealand
- Australia

social science

Identify and select countries of Oceania

Solution:
This country is Papua New Guinea.
Why does Papua New Guinea share its island with another country?
Papua New Guinea takes up the eastern half of the island of New Guinea. The western half is part of Indonesia, an Asian country.
Beginning in the 17 th century, several countries took control of different parts of the island of New Guinea. By 1922, Australia controlled the entire eastern half of the island, and the Netherlands controlled the western half. In 1963, control over the western half was transferred to Indonesia, which had just gained independence from the Netherlands. Many people in western New Guinea did not want to become part of Indonesia, though, and some people in this area are still fighting to leave Indonesia today. The eastern part gained independence from Australia in 1975 and became Papua New Guinea.


Question: What is the capital of Oregon?

Choices:
- Salem
- Denver
- Milwaukee
- Portland

social science

Solution: Salem is the capital of Oregon.


Question: What is the direction of this pull?

Choices:
- toward the pliers
- away from the pliers

A builder uses a pair of pliers to remove a nail from a board. A force from the pliers pulls the nail out of the wood.

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 pliers pull the nail. The direction of the pull is toward the pliers.


Question: What is the capital of Virginia?

Choices:
- Austin
- Arlington
- Montpelier
- Richmond

social science

Identify state capitals of the Southeast

Solution: Richmond is the capital of Virginia.


Question: What is the capital of Maryland?

Choices:
- Augusta
- Dover
- Annapolis
- Phoenix

social science

Identify state capitals of the Northeast

Solution: Annapolis is the capital of Maryland.


Question: What is the capital of Missouri?

Choices:
- Salem
- Saint Louis
- Jefferson City
- Kansas City

social science

Solution: Jefferson City is the capital of Missouri.


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

Choices:
- Can pennies hold more drops of water mixed with dish soap or water mixed with hand soap?
- Can pennies hold more drops of pure water or water mixed with hand soap?

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

Nate used a dropper to put equal-sized drops of pure water, one at a time, onto a penny. The drops stayed together and formed a dome on the penny's surface. Nate recorded the number of drops he could add before the water spilled over the edge of the penny. Then, he rinsed and dried the penny, and repeated the test using water mixed with hand soap. He repeated these trials on nine additional pennies. Nate compared the average number of pure water drops to the average number of water drops mixed with hand soap that he could add to a penny before the water spilled over.
Figure: a dome of water on the surface of a penny.

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 ocean is highlighted?

Choices:
- the Indian Ocean
- the Southern Ocean
- the Pacific 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 Southern Ocean.
The Southern Ocean reaches from the shores of Antarctica to 60° South latitude.


Question: Which of the following statements is supported by the passage?

Choices:
- Scientists can study air masses to predict weather events.
- Meteorologists are scientists who study meteors.

Meteorologists can make predictions about weather events. For example, the passage below describes how a meteorologist might use observations of Earth's atmosphere to predict a tornado event.
Figure: a tornado passing through a field.

natural science


Question: Will these magnets attract or repel each other?

Choices:
- attract
- repel

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: north and south.
Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S.
If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract.
If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

Solution:
To predict if these magnets will attract or repel, look at which poles are closest to each other.
Both poles of each magnet line up with both poles of the other magnet. The south pole of each magnet is closest to the north pole of the other magnet. Opposite poles attract. So, these magnets will attract each other.


Question: Which country is highlighted?

Choices:
- Solomon Islands
- the Marshall Islands
- Tonga
- Fiji

social science

Identify and select countries of Oceania

Solution: This country is Fiji.


Question: What evidence of an earthquake does this picture show?

Choices:
- Some of the houses have broken roofs and walls.
- The houses have windows.

This picture was taken after an earthquake. During an earthquake, the ground shakes.

natural science

Find evidence of changes to Earth's surface

Evidence is information that tells you something happened.
How do you look for evidence of a change to Earth's surface?
There are many ways to find evidence of a change to Earth's surface. One way is to look at a picture that was taken after the change.
Here are some examples of what the evidence for different changes might be:
Cause of the change | Evidence of the change
earthquake | cracks in the ground; houses with broken walls and roofs
volcanic eruption | melted rock on Earth's surface; smoke coming out of a hole in the ground
erosion | a canyon with a river flowing through it; a river carrying sand and mud
Be careful when you are looking for evidence!
A picture of Earth's surface can contain a lot of information. Some of that information might be evidence of a change to the surface, but some of it is not!
For example, a picture taken after an earthquake might show a blue sky. But the color of the sky is not evidence of an earthquake. So, that information is not evidence that an earthquake happened.


Question:
Is the following statement about our solar system true or false?
Three-quarters of the planets are larger than Venus.

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.

Solution: The table tells you that there are five planets larger than Venus: Earth, Jupiter, Saturn, Uranus, and Neptune. There are eight planets total. Five-eighths is less than three-quarters. So, five-eighths of the planets are larger than Venus.


Question: In this experiment, which were part of a control group?

Choices:
- the containers that did not get worms
- the containers that got worms

The passage below describes an experiment.

Susan wanted to set up a compost bin, where food could decompose, or break down, into soil fertilizer. She knew that worms can break down food. She wondered if adding worms to her compost bin would cause food to decompose faster.
Susan set up four small compost containers. She added the same amounts of fruit peels, vegetable scraps, and eggshells to each container. Then, she added worms to two of the containers but not to the other two. After one month, Susan weighed the amount of undecomposed food left in each container.
Figure: food decomposing in a compost bin.

natural science

Identify control and experimental groups

Experiments have variables, or parts that change. You can design an experiment to investigate whether changing a variable between different groups has a specific outcome.
For example, imagine you want to find out whether adding fertilizer to soil affects the height of pea plants. You could investigate this question with the following experiment:
You grow one group of pea plants in soil with fertilizer and measure the height of the plants. This group shows you what happens when fertilizer is added to soil. Since fertilizer is the variable whose effect you are investigating, this group is an experimental group.
You grow another group of pea plants in soil without fertilizer and measure the height of the plants. Since this group shows you what happens when fertilizer is not added to the soil, it is a control group.
By comparing the results from the experimental group to the results from the control group, you can conclude whether adding fertilizer to the soil affects pea plant height.

Solution: In this experiment, Susan investigated whether adding worms to compost containers affects how well food breaks down. There were no worms in the containers that did not get worms. So, they were part of a control group.


Question: What instrument does Yo-Yo play?

Choices:
- the violin
- the cello

Read the passage about Yo-Yo Ma.
Yo-Yo Ma is a famous cello player. He makes beautiful music. Yo-Yo's name comes from the Chinese word yo, which means "friendly." Yo-Yo's parents were from China. His mother was a singer, and his father was a music teacher.
Yo-Yo began playing the cello when he was only four years old. His father was his first teacher. Yo-Yo's father hoped that Yo-Yo would become a great cello player someday. Today, Yo-Yo is one of the best cello players in the world.

language science

Read and understand informational passages

Solution:
Look at the passage. It tells you what instrument Yo-Yo plays.
Yo-Yo Ma is a famous cello player. He makes beautiful music. Yo-Yo's name comes from the Chinese word yo, which means "friendly." Yo-Yo's parents were from China. His mother was a singer, and his father was a music teacher.


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

Choices:
- flexible
- salty
- smooth

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 flower petals are flexible, but the wax candle, the ice hockey rink, and the trombone are not.
Potato chips have a salty taste. The trombone is not salty.
A smooth object is not scratchy or rough. All four objects are smooth.
The property that all four objects have in common is smooth.


Question: What is the capital of Colorado?

Choices:
- Harrisburg
- Denver
- Colorado Springs
- Helena

social science

Solution: Denver is the capital of Colorado.


Question: Is a rubber balloon a solid, a liquid, or a gas?

Choices:
- a liquid
- a gas
- a solid

natural science

Identify and sort solids, liquids, and gases

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 are thicker than 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. The oxygen you breathe is a gas. The helium in a balloon is also a gas.

Solution: A rubber balloon is a solid. You can bend a balloon. But it will still have a size and shape of its own.


Question:
Is the following statement about our solar system true or false?
The volume of Mars is more than ten times as large as Mercury's.

Choices:
- true
- false

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, first 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
To multiply a number written in scientific notation by a power of 10, write the multiple of 10 as 10 raised to an exponent. Then, add the exponents. For example:
1.43 x 10^15 · 1000
= 1.43 x 10^15 · 10^3
= 1.43 x 10^(15 + 3)
= 1.43 x 10^18

Solution:
To determine if this statement is true, calculate the value of ten times the volume of Mercury.
Then compare the result to the volume of Mars. The volume of Mars is 1.63 x 10^11 km^3, which is less than 6.08 x 10^11 km^3. So, the volume of Mars is less than ten times as large as Mercury's.


Question: What is the capital of Maryland?

Choices:
- Providence
- Baltimore
- Montpelier
- Annapolis

social science

Identify state capitals of the Northeast

Solution: Annapolis is the capital of Maryland.


Question: Which continent is highlighted?

Choices:
- Australia
- Antarctica
- South America
- Asia

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 Australia.


Question: Will these magnets attract or repel each other?

Choices:
- repel
- attract

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 north pole of one magnet is closest to the north pole of the other magnet. Poles that are the same repel. So, these magnets will repel each other.


Question: What type of rock is conglomerate?

Choices:
- sedimentary
- igneous
- metamorphic

This is a piece of conglomerate. Conglomerate has grains of various sizes, such as sand, mud, and pebbles. Do you see the pebbles that are part of this rock?
Conglomerate forms when sediments of different sizes are deposited in one place. This usually happens in riverbeds. Conglomerate forms when layers of sand, mud, and pebbles are pressed together to form rock.

natural science

Classify rocks as igneous, sedimentary, or metamorphic

Igneous rock is formed when melted rock cools and hardens into solid rock. This type of change can occur at Earth's surface or below it.
Sedimentary rock is formed when layers of sediment are pressed together, or compacted, to make rock. This type of change occurs below Earth's surface.
Metamorphic rock is formed when a rock is changed by very high temperature and pressure. This type of change often occurs deep below Earth's surface. Over time, the old rock becomes a new rock with different properties.

Solution:
Conglomerate is a sedimentary rock. Like other sedimentary rocks, it forms from layers of sediment.
Material that is eroded in nature is called sediment. Sand, mud, and pebbles are all types of sediment. Over time, layers of these sediments can build up in places like riverbeds. The top layers press down on the bottom layers, squeezing out water and air. Conglomerate forms when the bottom layers of sediment are pressed together to form rock.


Question: Which country is highlighted?

Choices:
- Saint Lucia
- Jamaica
- Haiti
- Cuba

social science

Identify and select countries of the Caribbean

Solution: This country is Jamaica.


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

Choices:
- the amount of bacteria in the water before it was filtered
- whether the filter was clogged
- whether an inexpensive filter would become clogged more often

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.

Tyler was . At the plant, an expensive filter was used to remove disease-causing bacteria from the water. But over time, the filter would become clogged with bacteria. If the filter became clogged, the water would not move through quickly enough. Tyler had to decide when the filter was too clogged and needed to be replaced. So, during his inspection, Tyler checked the filter by measuring how quickly water moved through it.
Figure: an engineer at a water treatment plant.

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: What can Janet and Kari trade to each get what they want?

Choices:
- Janet can trade her tomatoes for Kari's sandwich.
- Kari can trade her almonds for Janet's tomatoes.
- Kari can trade her broccoli for Janet's oranges.
- Janet can trade her tomatoes for Kari'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.
Janet and Kari open their lunch boxes in the school cafeteria. Both of them could be happier with their lunches. Janet wanted broccoli in her lunch and Kari was hoping for tomatoes. Look at the images of their lunches. Then answer the question below.

social science

Solution:
Janet wanted broccoli in her lunch and Kari was hoping for tomatoes. Look at the labeled part of the images.
Janet has tomatoes. Kari has broccoli. They can trade tomatoes for broccoli to both be happier. Trading other things would not help either person get more items they want.


Question: Which animal's skin is better adapted as a warning sign to ward off predators?

Choices:
- lionfish
- impala

Golden dart frogs have poisonous glands in their brightly colored skin. The bright color serves as a warning sign that the animal is poisonous. The 's skin is adapted to ward off predators.
Figure: golden dart frog.

natural science

Animal adaptations: skins and body coverings

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors.
The color, texture, and covering of an animal's skin are examples of adaptations. Animals' skins can be adapted in different ways. For example, skin with thick fur might help an animal stay warm. Skin with sharp spines might help an animal defend itself against predators.

Solution:
Look at the picture of the golden dart frog.
The golden dart frog has poisonous glands in its brightly colored skin. Its skin is adapted to ward off predators. The bright colors serve as a warning sign that the golden dart frog is poisonous.
Now look at each animal. Figure out which animal has a similar adaptation.
The lionfish has venomous spines and brightly colored skin. Its skin is adapted to ward off predators.
The impala has yellow-brown fur. Its skin is not adapted to be a warning sign that wards off predators.


Question: Which property matches this object?

Choices:
- translucent
- 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.

Solution:
Look at the object.
Think about each property.
A translucent object lets light through. But you cannot see clearly through a translucent object. The crayons are not translucent.
A colorful object has one or more bright colors. The crayons are colorful.


Question: Which property matches this object?

Choices:
- bendable
- bouncy

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells.

Solution:
Look at the object.
Think about each property.
A bouncy object will bounce back from the floor if you drop it. The soccer shorts are not bouncy.
A bendable object can be bent without breaking. The soccer shorts are bendable.


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

Choices:
- Can pennies hold more drops of pure water or water mixed with hand soap?
- Can pennies hold more drops of water mixed with dish soap or water mixed with hand soap?

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

Tanner used a dropper to put equal-sized drops of pure water, one at a time, onto a penny. The drops stayed together and formed a dome on the penny's surface. Tanner recorded the number of drops he could add before the water spilled over the edge of the penny. Then, he rinsed and dried the penny, and repeated the test using water mixed with hand soap. He repeated these trials on nine additional pennies. Tanner compared the average number of pure water drops to the average number of water drops mixed with hand soap that he could add to a penny before the water spilled over.
Figure: a dome of water on the surface of a penny.

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 Barbara's experiment can best answer.

Choices:
- Do the temperatures inside boxes depend on the sizes of the boxes?
- Do the insides of white boxes get hotter than the insides of black boxes when the boxes are left in the sun?

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

Barbara glued lids onto 16 cardboard shoe boxes of equal size. She painted eight of the boxes black and eight of the boxes white. Barbara made a small hole in the side of each box and then stuck a thermometer partially into each hole so she could measure the temperatures inside the boxes. She placed the boxes in direct sunlight in her backyard. Two hours later, she measured the temperature inside each box. Barbara compared the average temperature inside the black boxes to the average temperature inside the white boxes.
Figure: a shoebox painted black.

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 2.
- The magnitude of the magnetic force is greater 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 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 1 than in Pair 2. So, the magnitude of the magnetic force is greater in Pair 1 than in Pair 2.


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

Choices:
- The magnetic force is stronger in Pair 2.
- The magnetic force is stronger in Pair 1.
- The strength 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.

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 stronger the magnetic force between two magnets, the more strongly the magnets attract or repel each other.

Solution:
Distance affects the strength of the magnetic force. But the distance between the magnets in Pair 1 and in Pair 2 is the same.
So, the strength of the magnetic force is the same in both pairs.


Question: Which animal is also adapted to be camouflaged in a sandy desert?

Choices:
- Namaqua chameleon
- fire salamander

Horned vipers live in the deserts of Africa and the Middle East. The  is adapted to be camouflaged in a sandy desert.
Figure: horned viper.

natural science

Animal adaptations: skins and body coverings

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors.
The color, texture, and covering of an animal's skin are examples of adaptations. Animals' skins can be adapted in different ways. For example, skin with thick fur might help an animal stay warm. Skin with sharp spines might help an animal defend itself against predators.

Solution:
Look at the picture of the horned viper.
The horned viper has sand-colored scales covering its body. It is adapted to be camouflaged in a sandy desert. The word camouflage means to blend in.
Now look at each animal. Figure out which animal has a similar adaptation.
The Namaqua chameleon has sand-colored scales covering its body. It is adapted to be camouflaged in a sandy desert.
The fire salamander has brightly colored skin. It is not adapted to be camouflaged in a sandy desert.


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

Choices:
- shiny
- slippery
- hard

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 hard object does not change shape when pressed or squeezed. All three objects are hard.
A slippery object is hard to hold onto or stand on. The building blocks and the magnifying glass are not slippery.
A shiny object reflects a lot of light. You can usually see your reflection in a shiny object. The metal bar and the magnifying glass are shiny, but the building blocks are not.
The property that all three objects have in common is hard.


Question: What is the capital of Iowa?

Choices:
- Jefferson City
- Des Moines
- Madison
- Cedar Rapids

social science

Solution: Des Moines is the capital of Iowa.


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

Choices:
- climate
- weather

Figure: Havana.
Havana is the capital of Cuba. The winds there were blowing from the east last weekend.
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.
Havana is the capital of Cuba. The winds there were blowing from the east last weekend.
The underlined part of the passage tells you about the wind direction in Havana last weekend. This passage describes the atmosphere at a certain place and time. So, this passage describes the weather.


Question: What is the capital of Iowa?

Choices:
- Davenport
- Helena
- Lansing
- Des Moines

social science

Solution: Des Moines is the capital of Iowa.


Question: Which of these continents does the prime meridian intersect?

Choices:
- North America
- Asia
- Africa

social science

Lines of latitude and lines of longitude are imaginary lines drawn on some globes and maps. They can help you find places on globes and maps.
Lines of latitude show how far north or south a place is. We use units called degrees to describe how far a place is from the equator. The equator is the line located at 0° latitude. We start counting degrees from there.
Lines north of the equator are labeled N for north. Lines south of the equator are labeled S for south. Lines of latitude are also called parallels because each line is parallel to the equator.
Lines of longitude are also called meridians. They show how far east or west a place is. We use degrees to help describe how far a place is from the prime meridian. The prime meridian is the line located at 0° longitude. Lines west of the prime meridian are labeled W. Lines east of the prime meridian are labeled E. Meridians meet at the north and south poles.
The equator goes all the way around the earth, but the prime meridian is different. It only goes from the North Pole to the South Pole on one side of the earth. On the opposite side of the globe is another special meridian. It is labeled both 180°E and 180°W.
Together, lines of latitude and lines of longitude form a grid. You can use this grid to find the exact location of a place.

Solution: The prime meridian is the line at 0° longitude. It intersects Africa. It does not intersect North America or Asia.


Question: What is the name of the colony shown?

Choices:
- Maryland
- New Jersey
- Virginia
- 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: Select the organism in the same species as the reticulated python.

Choices:
- Python bivittatus
- Python reticulatus
- Sciurus vulgaris

This organism is a reticulated python. Its scientific name is Python reticulatus.

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 reticulated python's scientific name is Python reticulatus.
Python reticulatus has the same scientific name as a reticulated python. So, these organisms are in the same species.
Sciurus vulgaris does not have the same scientific name as a reticulated python. So, Python reticulatus and Sciurus vulgaris are not in the same species.
Python reticulatus is in the same genus as Python bivittatus, but they are not in the same species.
Organisms in the same species have the same scientific names. Python reticulatus and Python bivittatus are different species within the same genus.


Question: During this time, thermal energy was transferred from () to ().

Choices:
- each refrigerator . . . the surroundings
- the surroundings . . . each refrigerator

Two identical refrigerators in a restaurant kitchen lost power. The door of one fridge was slightly open, and the door of the other fridge was closed. This table shows how the temperature of each refrigerator changed over 10minutes.

natural science

A change in an object's temperature indicates a change in the object's thermal energy:
An increase in temperature shows that the object's thermal energy increased. So, thermal energy was transferred into the object from its surroundings.
A decrease in temperature shows that the object's thermal energy decreased. So, thermal energy was transferred out of the object to its surroundings.

Solution: The temperature of each refrigerator increased, which means that the thermal energy of each refrigerator increased. So, thermal energy was transferred from the surroundings to each refrigerator.


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

Choices:
- The magnetic force is weaker in Pair 2.
- The strength of the magnetic force is the same in both pairs.
- The magnetic force is weaker 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 stronger the magnetic force between two magnets, the more strongly the magnets attract or repel each other.
You can change the strength of a magnetic force between two magnets by changing the distance between them. The magnetic force is weaker when the magnets are farther apart.

Solution:
Distance affects the strength of the magnetic force. When magnets are farther apart, the magnetic force between them is weaker.
The magnets in Pair 1 are farther apart than the magnets in Pair 2. So, the magnetic force is weaker in Pair 1 than in Pair 2.


Question: Can Asimina triloba cells make their own food?

Choices:
- yes
- no

This organism is Asimina triloba. It is a member of the plant kingdom.
Asimina triloba is commonly called the pawpaw. Pawpaw trees grow in the southeastern part of the United States. They have large, sweet fruit. The fruit is sometimes called a prairie banana.

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: Asimina triloba is a plant. Plant cells can make their own food. Plant cells make food using photosynthesis.


Question: Which of the following was a dependent variable in this experiment?

Choices:
- the amount of oxygen in the tanks
- the species of algae

The passage below describes an experiment. Read the passage and think about the variables that are described.

Dr. Hardin collected two species of algae, Chlorella rotunda and Tetraselmis cordiformis. He wanted to know whether one species released more oxygen as it grew than the other species.
To find out, Dr. Hardin prepared six culture tanks. He filled each tank with the same amount of a mixture of water and nutrients. Then, he added 1,000 live algae cells to each tank and sealed the tank. In three of the tanks, he added C. rotunda cells. In the other three, he added T. cordiformis cells. After five days, Dr. Hardin measured the amount of oxygen in each culture tank.
Hint: An independent variable is a variable whose effect you are investigating. A dependent variable is a variable that you measure.
Figure: growing algae in culture tanks.

natural science

Identify independent and dependent variables

Experiments have variables, or parts that change. You can design an experiment to find out how one variable affects another variable. For example, imagine that you want to find out if fertilizer affects the number of tomatoes a tomato plant grows. To answer this question, you decide to set up two equal groups of tomato plants. Then, you add fertilizer to the soil of the plants in one group but not in the other group. Later, you measure the effect of the fertilizer by counting the number of tomatoes on each plant.
In this experiment, the amount of fertilizer added to the soil and the number of tomatoes were both variables.
The amount of fertilizer added to the soil was an independent variable because it was the variable whose effect you were investigating. This type of variable is called independent because its value does not depend on what happens after the experiment begins. Instead, you decided to give fertilizer to some plants and not to others.
The number of tomatoes was a dependent variable because it was the variable you were measuring. This type of variable is called dependent because its value can depend on what happens in the experiment.


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

Choices:
- cyclopropane
- chloroform
- nitrogen

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: Does this passage describe the weather or the climate?

Choices:
- climate
- weather

Figure: the Red Sea.
The Red Sea is a popular place for windsurfing. Wind speeds reached 30 miles per hour there on Thursday.
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.
The Red Sea is a popular place for windsurfing. Wind speeds reached 30 miles per hour there on Thursday.
The underlined part of the passage tells you about the wind speed at the Red Sea on Thursday. This passage describes the atmosphere at a certain place and time. So, this passage describes the weather.


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

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

The diagram below is a model of two solutions. Each blue 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 blue particles represent the solute. To figure out which solution has a higher concentration of blue particles, look at both the number of blue particles and the volume of the solvent in each container.
Use the concentration formula to find the number of blue particles per milliliter.
Solution A has more blue particles per milliliter. So, Solution A has a higher concentration of blue particles.


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.

Solution:
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 country is highlighted?

Choices:
- the Dominican Republic
- Grenada
- Jamaica
- Trinidad and Tobago

social science

Identify and select countries of the Caribbean

Solution: This country is Trinidad and Tobago.


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

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

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.
Brandon and Derek open their lunch boxes in the school cafeteria. Neither Brandon 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.
Brandon's lunch Derek's lunch

social science

Solution:
Look at the table and images.
Brandon 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 can Connor and Maura trade to each get what they want?

Choices:
- Connor can trade his tomatoes for Maura's carrots.
- Maura can trade her broccoli for Connor's oranges.
- Connor can trade his tomatoes for Maura's broccoli.
- Maura can trade her almonds for Connor's tomatoes.

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.
Connor and Maura open their lunch boxes in the school cafeteria. Neither Connor nor Maura 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.
Connor's lunch Maura's lunch

social science

Solution:
Look at the table and images.
Connor wants broccoli. Maura 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: 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 2.
- The magnitude of the magnetic force is the same in both pairs.
- 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.

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: Which month is the coolest on average in Detroit?

Choices:
- January and February
- November and December
- June and July

Use the graph to answer the question below.

natural science

Scientists record climate data from places around the world. Temperature is one type of climate data. Scientists collect data over many years. They can use this data to calculate the average temperature for each month. The average temperature can be used to describe the climate of a location.
A line graph can be used to show the average temperature each month. Months with higher dots on the graph have higher average temperatures.

Solution:
To describe the average temperature trends in Detroit, look at the graph.
Choice "Feb" is incorrect.
Choice "Jun" is incorrect.
Choice "Jul" is incorrect.
Choice "Nov" is incorrect.
Choice "Dec" is incorrect.
Choice "Jan" is incorrect.
The average temperatures in January and February are between 25°F and 30°F. These months have the lowest average temperatures of all of the months. So, they are the coolest months on average.


Question: Which country is highlighted?

Choices:
- Jamaica
- Saint Lucia
- Barbados
- Saint Vincent and the Grenadines

social science

Identify and select countries of the Caribbean

Solution: This country is Saint Lucia.


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

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

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: Which state is highlighted?

Choices:
- Nebraska
- North Dakota
- Michigan
- Minnesota

social science

Solution: This state is North Dakota.


Question: Which better describes the Catoctin Mountain Park ecosystem?

Choices:
- It has cold, wet winters. It also has soil that is rich in nutrients.
- It has cold, wet winters. It also has soil that is poor in nutrients.

Figure: Catoctin Mountain Park.
Catoctin Mountain Park is a temperate deciduous forest ecosystem in Maryland.

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 temperate deciduous forest is a type of ecosystem. Temperate deciduous forests have the following features: warm, wet summers and cold, wet winters, soil that is rich in nutrients, and only a few types of trees. So, Catoctin Mountain Park has cold, wet winters. It also has soil that is rich in nutrients.


Question: Select the reptile below.

Choices:
- clownfish
- helmeted iguana

Reptiles have scaly, waterproof skin. Most reptiles live on land. A coral snake is an example of a reptile.

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.
Clownfish live with animals called anemones. In the image of the clownfish, you can see the green anemone behind the clownfish.
A helmeted iguana is a reptile. It has scaly, waterproof skin.
Iguanas are a type of lizard. Iguanas eat plants and fruit.