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

Example Input: A change of season and less food usually cause certain animals to migrate.
Example Output: Which two environmental changes usually cause certain animals to migrate?

Example Input: The opening in the front of the eye is called pupil.
Example Output: What is the opening in the front of the eye called?

Example Input: A pregnant woman should avoid toxic substances while pregnant.
Example Output:
What should a pregnant woman avoid while pregnant?