Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Q: Humans have 23 pairs pairs of chromosomes.

A: How many pairs of chromosomes do human have ?
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Q: Over 90% of the energy we use comes originally from the sun.

A: Over 90% of the energy we use comes originally from what?
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Q: None type of membrane are ribosomes surrounded by.

A:
Which type of membrane are ribosomes surrounded by?
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