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: A large log placed in a fire will burn relatively slowly. If the same mass of wood were added to the fire in the form of small twigs, they would burn much more quickly. This is because the twigs provide a greater surface area than the log does. An increase in the surface area of a reactant increases the rate of a reaction. Surface area is larger when a given amount of a solid is present as smaller particles. A powdered reactant has a greater surface area than the same reactant as a solid chunk. In order to increase the surface area of a substance, it may be ground into smaller particles or dissolved into a liquid. In solution, the dissolved particles are separated from each other and will react more quickly with other reactants.
Story: Two groups of teens studied fire for the physics class. Group S made a fire using large logs, while group F made a fire using small twigs and sawdust. Both groups used the same volume of wood.

Answer: Which group made a fire from fewer particles of wood?

Question: Background Paragraph: Hemophilia is the name of a group of hereditary diseases that affect the body's ability to control blood clotting. Hemophilia is caused by a lack of clotting factors in the blood. Clotting factors are normally released by platelets. Since people with hemophilia cannot produce clots, any cut can put a person at risk of bleeding to death. The risk of internal bleeding is also increased in hemophilia, especially into muscles and joints. This disease affected the royal families of Europe.
Story: Two twin sisters were taken to the doctor's office by their parents. It turned out that Mary had hemophilia while Ann didn't have any blood disease.

Answer: Which sister didn't have the same disease as the royal families of Europe did?

Question: Background Paragraph: 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.
Story: An anthropologist gathered observations for two native tribes from southern Africa. He noticed that both tribes spend the majority of the day outside, and therefore they are both exposed to fairly high amounts of UV light. He also quickly realized that one key difference between the tribes was that members of tribe A had dark skin, while members of tribe B had light skin.

Answer:
Members of which tribe will be at greater risk for vitamin D deficiency?