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

Ex Input:
The mesopause is at the top of the mesosphere.

Ex Output:
What is at the top of the mesosphere?


Ex Input:
Ionic compounds contain cations and anions rather than discrete neutral molecules.

Ex Output:
Ionic compounds contain cations and anions rather than what?


Ex Input:
Comprised mainly of collagen and associated with long bones and the skull, hyaline is the most widespread type of collagen.

Ex Output:

Comprised mainly of collagen and associated with long bones and the skull, hyaline is the most widespread type of what?