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

Answer: How many years ago may the earliest fungi have evolved?

Question: Sexual reproduction, in general, relies on sets of cells that are precursors for eggs and sperm.

Answer: What kind of reproduction, in general, relies on sets of cells that are precursors for eggs and sperm?

Question: It is dark does photosynthesis not occur in the deep-water zone.

Answer:
Why does photosynthesis not occur in the deep-water zone?