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: Most of the digestion reactions occur in the small intestine.

Answer: Where do most of the digestion reactions occur?

Question: Producing sperm and secreting testosterone are the main functions of male reproductive system system.

Answer: Producing sperm and secreting testosterone are the main functions of what system?

Question: Rock containing fossilized seashells found on a mountaintop of the following provides the best evidence that earth has evolved over geologic time.

Answer:
Which of the following provides the best evidence that Earth has evolved over geologic time?