[Q]: Chemical equilibrium was studied by French chemist Henri Le Chatelier (1850-1936), and his description of how a system at equilibrium responds to a change in conditions has become known as Le Chatelier's principle . This principle states that when a chemical system is at equilibrium and is disturbed by a stress, the system will respond by attempting to counteract that stress until a new equilibrium is established. Stresses to a chemical system include changes in the concentrations of reactants or products, changes in the temperature of the system, or changes in the pressure of the system. We will discuss each of these stresses separately. In each case, the change to the equilibrium position will cause either the forward or reverse reaction to be favored over the opposite process. When the forward reaction is favored, the concentrations of the products increase, and the concentrations of the reactants decrease. When the reverse reaction is favored, the concentrations of the products decrease, and the concentrations of the reactants increase. John was trying to reenact Le Chatelier's principle. To that end, he conducted four tests, test A, test B, test C, and test D. In test A, he didn't input any stress to a chemical system in equilibrium. But In test B, he put some stress to the same system. In test C, he observed a forward reaction, but in test D, he observed a reverse reaction. In which test Le Chatelier's principle had been applied, test A or test B?
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[A]: test B

[Q]: The lungs of mammals are unique in having alveoli . These are tiny, sac-like structures. Each alveolus is surrounded by a network of very small blood vessels (see Figure below ). Because there are millions of alveoli in each lung, they greatly increase the surface area for gas exchange between the lungs and bloodstream. Human lungs, for example, contain about 300 million alveoli. They give the lungs a total surface area for gas exchange of up to 90 square meters (968 square feet). That's about as much surface area as one side of a volleyball court! Two students learned about respiratory systems in animals. Dana learned more about mammalian lungs, while Barry learned more about the lungs of birds. Which student learned more about surface area for gas exchange between the lungs and bloodstream?
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[A]: Dana

[Q]: Farsightedness, or hyperopia, is the condition in which distant objects are seen clearly, but nearby objects appear blurry. It occurs when the eyeball is shorter than normal (see Figure below ). This causes images to be focused in a spot that would fall behind the retina (if light could pass through the retina). Hyperopia can be corrected with convex lenses. The lenses focus images farther forward in the eye, so they fall on the retina instead of behind it. Two people went to the eye doctor's office for an annual exam; James had farsightedness, while Bob had perfect 20/20 vision. Which person saw more distant objects clearly?
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[A]: James

[Q]: Hepatitis B is a disease of the liver. It is caused by a virus called hepatitis B, which can be passed through sexual activity. Hepatitis B causes vomiting. It also causes yellowing of the skin and eyes. The disease goes away on its own in some people. Other people are sick for the rest of their lives. In these people, the virus usually damages the liver. It may also lead to liver cancer. Medicines can help prevent liver damage in these people. There is also a vaccine to protect against hepatitis B. Anthony is going in for a doctors appointment. He hasn't been feeling well and has been vomiting. When he talks to his doctor the doctor can tell immediately what's wrong. Anthony's physical appearance immediately tells the doctor that he likely has hepatitis B. Given a person's eyes and skin tone appear to be yellow and they experience vomiting, will the chances that they have hepatitis B increase or decrease?
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[A]:
increase