Question: I read this background article the other day: Unfortunately, the layer of good ozone is being destroyed by air pollution. The chief culprits are chlorine and bromine gases. They are released in aerosol sprays, coolants, and other products. Loss of ozone has created an ozone hole over Antarctica. Ozone depletion results in higher levels of UV radiation reaching Earth. In humans, this increases skin cancers and eye cataracts. It also disturbs the nitrogen cycle, kills plankton, and disrupts ocean food webs. The total loss of the ozone layer would be devastating to most life. It’s rate of loss has slowed with restrictions on pollutants, but it is still at risk.  I am facing a new situation today: The researches studied the atmosphere in Antarctica, and close to Greenland. They found out there's an ozone hole over Antarctica.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which landmass didn't have its atmosphere destroyed by bromine gasses?
Answer: Greenland

Question: I read this background article the other day: The epidermis also contains melanocytes, which are cells that produce melanin. Melanin is the brownish pigment that gives skin much of its color. Everyone has about the same number of melanocytes, but the melanocytes of people with darker skin produce more melanin. The amount of melanin produced is determined by heredity and exposure to UV light, which increases melanin output. Exposure to UV light also stimulates the skin to produce vitamin D. Because melanin blocks UV light from penetrating the skin, people with darker skin may be at greater risk of vitamin D deficiency.  I am facing a new situation today: Jacob has lived in a city in Sweden for most of his life. His favorite hobbies are reading and playing videogames so he rarely goes outside. Even as a kid, he almost never played outside and instead was in his house most of the time. Martin lives in the middle of the Sahara desert in a small town. The sun almost never stops beating down on Martin during the day and it's hard to find shade where he lives.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Is Jacob more or less likely than Martin to have a vitamin D deficiency?
Answer: less

Question: I read this background article the other day: If a solution has a higher concentration of hydronium ions than pure water, it has a pH lower than 7. A solution with a pH lower than 7 is called an acid . As the hydronium ion concentration increases, the pH value decreases. Therefore, the more acidic a solution is, the lower its pH value is. Did you ever taste vinegar? Like other acids, it tastes sour. Stronger acids can be harmful to organisms. For example, stomach acid would eat through the stomach if it were not lined with a layer of mucus. Strong acids can also damage materials, even hard materials such as glass.  I am facing a new situation today: Alexiev and Sabrina were enthusiastic chemistry students completing the first experiment of their new course. They both started the experiment with pure water, and had to perform different experimental protocols to make changes to the water. At the end of the experiment, both of them measured the concentration of hydronium ions present in their reaction mixtures. Alexiev had a high concentration of hydronium ions present, while Sabrina had a low concentration present in her mixture.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which person's mixture, Alexiev's or Sabrina's, has a higher pH value at the end?
Answer:
Sabrina's