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

Ex Input:
Radioactive decay can give off energy and particles.

Ex Output:
Radioactive decay can give off energy and what else?

Ex Input:
Very low density is the concentration of gas molecules in the mesosphere.

Ex Output:
What is the concentration of gas molecules in the mesosphere?

Ex Input:
The mammalian middle ear has three bones.

Ex Output:
How many bones does the mammalian middle ear have?