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: Protons and neutrons are made of quarks, which are fundamental particles of matter.

Answer: A fundamental particle of matter, protons and neutrons are made of these?


Question: Renewable energy sources emit fewer or no greenhouse gases.

Answer: What type energy sources emit fewer or no greenhouse gases?


Question: Epididymis is the third male reprodutive structure after the penis and testes.

Answer:
What is the third male reprodutive structure after the penis and testes?