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: It takes about one year for earth to orbit the sun.

Answer: Which of these takes about one year to complete?


Question: Mechanical waves term describes waves that travel through matter.

Answer: What term describes waves that travel through matter?


Question: Nonmetals is the second largest class of elements.

Answer:
What is the second largest class of elements?