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

Q: Control rods play an important role in the modulation of the nuclear chain reaction.

A: What play an important role in the modulation of the nuclear chain reaction?
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Q: Some materials have negative heats of solution; the dissolution of one of these solutes in water is called?

A: Some materials have negative heats of solution; the dissolution of one of these solutes in water is called?
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Q: Chordates is the only animal phyla that does not consist exclusively of invertebrates.

A:
What is the only animal phyla that does not consist exclusively of invertebrates?
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