Please answer this: I read this background article the other day: Acceleration is a measure of the change in velocity of a moving object. It measures the rate at which velocity changes. Velocity, in turn, is a measure of the speed and direction of motion, so a change in velocity may reflect a change in speed, a change in direction, or both. Both velocity and acceleration are vectors. A vector is any measurement that has both size and direction. People commonly think of acceleration as in increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative and called deceleration. A change in direction without a change in speed is acceleration as well. I am facing a new situation today: Johnny is playing with a toy train set his parents bought him. The controls for this train set allow him to make it go faster or slower and it even has a rail switch to make it travel on different tracks branching off to the left or right. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Will making the train switch to a different track be considered acceleration, yes or no.
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Answer: yes
Problem: I read this background article the other day: The earliest members of the human species evolved around 200,000 years ago in Africa. Early humans lived in small populations of nomadic hunters and gatherers. Human beings remained in Africa until about 40,000 years ago. After that, they spread throughout Europe, Asia, and Australia. By 10,000 years ago, the first human beings colonized the Americas. During this long period of time, the total number of human beings increased very slowly. Birth rates were fairly high but so were death rates, producing low rates of population growth. I am facing a new situation today: Two colleagues studied human evolution, Dan studied early humans, from around 200,000 years ago, while Bob studied human settlements from 10,000 years ago. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which student learned more about nomadic gatherers?

A: Dan
Problem: Given the question: I read this background article the other day: Reptiles are a class of animals comprising turtles, tuataras, lizards, snakes and crocodiles. They are tetrapods, but the snakes and a few species of lizard either have no limbs or their limbs are much reduced in size. Their bones are better ossified and their skeletons stronger than those of amphibians. The teeth are conical and mostly uniform in size. The surface cells of the epidermis are modified into horny scales which create a waterproof layer. Reptiles are unable to use their skin for respiration as do amphibians and have a more efficient respiratory system drawing air into their lungs by expanding their chest walls. The heart resembles that of the amphibian but there is a septum which more completely separates the oxygenated and deoxygenated bloodstreams. The reproductive system has evolved for internal fertilization, with a copulatory organ present in most species. The eggs are surrounded by amniotic membranes which prevents them from drying out and are laid on land, or develop internally in some species. The bladder is small as nitrogenous waste is excreted as uric acid.Turtles are notable for their protective shells. They have an inflexible trunk encased in a horny carapace above and a plastron below. These are formed from bony plates embedded in the dermis which are overlain by horny ones and are partially fused with the ribs and spine. The neck is long and flexible and the head and the legs can be drawn back inside the shell. Turtles are vegetarians and the typical reptile teeth have been replaced by sharp, horny plates. In aquatic species, the front legs are modified into flippers.Tuataras superficially resemble lizards but the lineages diverged in the Triassic period. There is one living species, Sphenodon punctatus. The skull has two openings (fenestrae) on either side and the jaw is rigidly attached to the skull. There is one row of teeth in the lower jaw and this fits between the two rows in the upper jaw when the animal chews. The teeth are merely projections of bony material from the jaw... I am facing a new situation today: An archipelago in the Indian ocean included two very different islands. Snake island was a reptile paradise, inhabited by many species of reptiles. Bird island had few reptiles on it, but had various birds inhabiting it. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which island was inhabited by fewer turtles?
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The answer is:
Bird
input question: I read this background article the other day: In grassland, much of the organic matter added to the soil is from the deep, fibrous, grass root systems. By contrast, tree leaves falling on the forest floor are the principal source of soil organic matter in the forest. Another difference is the frequent occurrence in the grasslands of fires that destroy large amounts of aboveground material but stimulate even greater contributions from roots. Also, the much greater acidity under any forests inhibits the action of certain soil organisms that otherwise would mix much of the surface litter into the mineral soil. As a result, the soils under grasslands generally develop a thicker A horizon with a deeper distribution of organic matter than in comparable soils under forests, which characteristically store most of their organic matter in the forest floor (O horizon) and thin A horizon. I am facing a new situation today: In the Kenya-Tanzania border Kenyan grassland gradually merges into Tanzanian forest. Though they had similar soil to start with millions of years ago, today they are two different habitats. At present, Kenya has one of the largest contiguous grassland in Africa. On the other hand, Tanzania boasts one of the largest forest cover in Africa. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Would Kenya have less or more organic matter stored in the "O horizon" than Tanzania????
output answer: less
I read this background article the other day: About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. I am facing a new situation today: Peter visited two mountain ranges last summer. The Ozarks in Missouri, and the more massive and younger Colorado Rockies. He loved both ranges, but liked the caves systems and blue holes in the Ozarks a bit more. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which rocks are less soluble, the ones from the Ozarks, or the ones from the Rockies?
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Answer: Rockies
Q: I read this background article the other day: Cancer is a disease that causes cells to divide out of control. Normally, the body has systems that prevent cells from dividing out of control. But in the case of cancer, these systems fail. Cancer is usually caused by mutations. Mutations are random errors in genes. Mutations that lead to cancer usually happen to genes that control the cell cycle. Because of the mutations, abnormal cells divide uncontrollably. This often leads to the development of a tumor. A tumor is a mass of abnormal tissue. As a tumor grows, it may harm normal tissues around it. Anything that can cause cancer is called a carcinogen . Carcinogens may be pathogens, chemicals, or radiation. I am facing a new situation today: Jason recently learned that he has cancer. After hearing this news, he convinced his wife, Charlotte, to get checked out. After running several tests, the doctors determined Charlotte has no cancer, but she does have high blood pressure. Relieved at this news, Jason was now focused on battling his cancer and fighting as hard as he could to survive. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Who least likely had a mutation in their genes?
A:
Charlotte