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

Q: 600 million many years ago may the earliest fungi have evolved.

A: How many years ago may the earliest fungi have evolved?
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Q: Three many families are known quarks divided into.

A: How many families are known quarks divided into?
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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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