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

Ex Input:
Superior sagittal sinus is the largest of the sinuses.

Ex Output:
What is the largest of the sinuses?

Ex Input:
Intraplate earthquakes occur because solid lithosphere travels on a round planet.

Ex Output:
What occur because solid lithosphere travels on a round planet?

Ex Input:
The cells in the follicle undergo physical changes and produce a structure called a corpus luteum.

Ex Output:
The cells in the follicle undergo physical changes and produce a structure called a what?