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: Diffraction is the phenomenon in which light and sound waves become circular at the point source of a barrier.

Answer: What is the phenomenon in which light and sound waves become circular at the point source of a barrier?


Question: The male reproductive system consists of structures that produce sperm and secrete testosterone.

Answer: What does the male reproductive system consist of?


Question: The mild oxidation of thiols gives compounds called disulfides.

Answer:
The mild oxidation of thiols gives compounds called what?