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

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

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


Input: Consider Input: Line graphs are especially useful for showing changes over time.

Output: Line graphs are especially useful for showing changes over what?


Input: Consider Input: Water is at the neutrality, 7 point on the ph scale.


Output: At what point is water on the ph scale?