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

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

There are three quarks in each proton and neutron.
How many quarks are in each proton and neutron?

Depth and density influence the pressure of fluids.
What two factors influence the pressure of fluids?