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: The pupil is the name of the black opening in the eye that lets light enter.

Answer: What is the name of the black opening in the eye that lets light enter?


Question: Mucous does the esophagus produce for lubrication.

Answer: What does the esophagus produce for lubrication?


Question: Secondary alcohol forms a ketone when oxidized.

Answer:
What forms a ketone when oxidized?