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."
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Question: Background Paragraph: Surface temperature differences in turn cause pressure differences. A hot surface warms the air above it causing it to expand and lower the density and the resulting surface air pressure. The resulting horizontal pressure gradient moves the air from higher to lower pressure regions, creating a wind, and the Earth's rotation then causes deflection of this air flow due to the Coriolis effect. The simple systems thus formed can then display emergent behaviour to produce more complex systems and thus other weather phenomena.  Large scale examples include the Hadley cell while a smaller scale example would be coastal breezes. 
Story: Mark was visiting southern Africa as an exchange student. He was amazed by the beauty of Namib Desert, which is located mostly in Namibia. He kind of enjoyed the hot surface of the desert. Next to Namib desert is the grasslands of  Botswana. He noticed that the surface temperature was much lower there.

Answer: Which place would have higher air density, Namib Desert or Grasslands in Botswana?


Question: Background Paragraph: Beginning in September 2012, the U.S. Food and Drug Administration will require larger, more prominent cigarette health warnings on all cigarette packaging and advertisements in the United States. These warnings are a significant advancement in communicating the dangers of smoking. These new cigarette health warnings contains nine different warnings that will increase awareness of the specific health risks associated with smoking, such as death, addiction, lung disease, cancer, stroke and heart disease. These warnings include:. 
Story: David collects cigarette packs of different years. He found that two of his packs, pack A and pack B, are very different. Pack A is from before September 2012, and pack B is from after September 2012. He started searching on the internet to find out why the packs were different.

Answer: Which pack would be less efficient at communicating dangers of smoking, pack A or pack B?


Question: Background Paragraph: A dilution effect is seen when animals living in a group "dilute" their risk of attack, each individual being just one of many in the group. George C. Williams and W.D. Hamilton proposed that group living evolved because it provides benefits to the individual rather than to the group as a whole, which becomes more conspicuous as it becomes larger. One common example is the shoaling of fish. Experiments provide direct evidence for the decrease in individual attack rate seen with group living, for example in Camargue horses in Southern France. The horse-fly often attacks these horses, sucking blood and carrying diseases. When the flies are most numerous, the horses gather in large groups, and individuals are indeed attacked less frequently. Water striders are insects that live on the surface of fresh water, and are attacked from beneath by predatory fish. Experiments varying the group size of the water striders showed that the attack rate per individual water strider decreases as group size increases. 
Story: Kenya's Masai Mara wildebeest migration is one of the greatest spectacles in the natural world. Every year thousands of wildebeests cross the Mara river. John went to see the migration last year. He noticed that the wildebeests crossed the the river in a very large group. He noted that as case A. His guide told him that is not the case in other times of the year. The wildebeests cross the river in smaller groups in other times. John noted that as case B. The guide added that in both cases on thing is constant, they are attacked by the lions.

Answer:
In case A would the wildebeests have lower or higher risk of attack from the lions than in case B?