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

Ex Input:
The female reproductive system consists of structures that produce eggs, secrete female sex hormones, and ultimately enable birth of a fetus.

Ex Output:
What system consists of structures that produce eggs, secrete female sex hormones, and ultimately enable birth of a fetus?


Ex Input:
If two populations do not mate and produce fertile offspring, separate species result.

Ex Output:
If two populations do not mate and produce fertile offspring, what results?


Ex Input:
Spring tides are created when the sun and moon's tides match.

Ex Output:

Which type of tides are created when the sun and moon's tides match?