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

Q: Virtually all aquatic organisms depend directly or indirectly on protists for food.

A: Virtually all aquatic organisms depend directly or indirectly on what for food?
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Q: The behavior of ideal gases is explained by kinetic molecular theory.

A: The behavior of ideal gases is explained by what theory of gases?
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Q: Coal is the source of most electricity.

A:
What is the source of most electricity?
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