Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Q: Incubation is when birds keep their eggs warm while the embryos inside develop.

A: What is it called when birds keep their eggs warm while the embryos inside develop?
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Q: A fewer predators is most likely to cause the number of rabbits living in an area to increase.

A: Which factor is most likely to cause the number of rabbits living in an area to increase?
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Q: When you add moles of gas to a baloon by blowing it up, the volume increases.

A:
What happens to the volume of a balloon when you add moles of gas to it by blowing up?
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