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

Q: A vapor light produces visible light by electroluminescence process.

A: A vapor light produces visible light by what process?
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Q: Mercury is not a solid even at room temperature.

A: Which metal is not a solid even at room temperature?
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Q: Macroevolution happens when forces of evolution work over a long period of time.

A:
What happens when forces of evolution work over a long period of time?
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