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

[Q]: Through tubular ducts part do exocrine glands discharge their contents.
[A]: Through what part do exocrine glands discharge their contents?

[Q]: The majority of human genes have two or more possible alleles.
[A]: How many possible alleles do the majority of human genes have?

[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?