Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
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Question: Aerobic exercise helps improve the cardiovascular system, while anaerobic exercise causes muscles to get bigger and stronger.

Answer: Aerobic exercise helps improve the cardiovascular system, while what exercise causes muscles to get bigger and stronger?


Question: The seven unique crystal types are defined by faces parts of themselves (parts that intersect at various angles).

Answer: The seven unique crystal types are defined by what parts of themselves (parts that intersect at various angles)?


Question: From observations as simple as blowing up a balloon, it is clear that increasing the amount of gas increases the volume.

Answer:
From observations as simple as blowing up a balloon, it is clear that increasing the amount of gas increases what else?