instruction:
You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You need to come up with a question about the story that requires an understanding of the relationship described in the background paragraph. The generated question should not be answerable without both the background and story. Write a question about the story that requires a relationship in the background paragraph to answer. Check whether your question requires both the background paragraph and the story to answer. If your question can be answered by only one of these, try to rewrite your question so that it requires both. Note that "flipping" a word in the question can give rise to a new question where the answer will be different from the original question. Often, "flipping" a word gives rise to flipping the direction of the relationship, for example, from "increase" to "decrease."
question:
Background Paragraph: Recall that air pollution is due to chemical substances and particles released into the air mainly by human actions. When most people think of air pollution, they think of the pollution outdoors. But it is just as easy to have indoor air pollution. Your home or school classroom probably doesn't get much fresh air. Sealing up your home reduces heating and cooling costs. But this also causes air pollution to stay trapped indoors. And people today usually spend a majority of their time indoors. So exposure to indoor air pollution can become a significant health risk. 
Story: James spent a lot of time indoors, and didn't get out much like Rob, his friend, who loved outdoors stuff.
answer:
Which friend breathes less fresh air on a daily basis?


question:
Background Paragraph: We all enjoy a cool dip in a swimming pool on a hot day, but we may not realize the work needed to keep that water safe and healthy. The ideal pH for a swimming pool is around 7.2. The pH will change as a result of many factors. Adjustment can be accomplished with different chemicals depending on the tested pH. High pH can be lowered with liquid HCl (unsafe material) or sodium bisulfate. The bisulfate anion is a weak acid and can dissociate partially in solution. To increase pH, use sodium carbonate. The carbonate anion forms an equilibrium with protons that results in some formation of carbon dioxide. 
Story: Tom and John are both pool owners. Tom prefers to use sodium bisulfate in his pool because he enjoys the smell. John, however, prefers using sodium carbonate in his pool because he believes it helps keep pests away.
answer:
Whose pool will have a higher pH?


question:
Background Paragraph: Animals may avoid becoming prey by living out of sight of predators, whether in caves, burrows, or by being nocturnal. Nocturnality is an animal behavior characterized by activity during the night and sleeping during the day. This is a behavioral form of detection avoidance called crypsis used by animals to either avoid predation or to enhance prey hunting. Predation risk has long been recognized as critical in shaping behavioral decisions. For example, this predation risk is of prime importance in determining the time of evening emergence in echolocating bats. Although early access during brighter times permits easier foraging, it also leads to a higher predation risk from bat hawks and bat falcons. This results in an optimum evening emergence time that is a compromise between the conflicting demands.Another nocturnal adaptation can be seen in kangaroo rats. They forage in relatively open habitats, and reduce their activity outside their nest burrows in response to moonlight. During a full moon, they shift their activity towards areas of relatively dense cover to compensate for the extra brightness. 
Story: Nate and Andy were two zoologists. They have been studying the characteristics of nocturnal and diurnal animals. Andy studied nocturnal animals, while Nate studied diurnal animals.
answer:

Which zoologist learned less about animals that are active during the night?