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: Bacteria is usually the prey of a protist.

Answer: What is usually the prey of a protist?


Question: Mercury is not a solid even at room temperature.

Answer: Which metal is not a solid even at room temperature?


Question: Nonvascular plants were the first plants to evolve.

Answer:
What were the first plants to evolve?