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

Ex Input:
A student should use a balance to compare the masses of two small rocks.

Ex Output:
Which tool should a student use to compare the masses of two small rocks?

Ex Input:
Proteins are long chains of amino acids.

Ex Output:
What are long chains of amino acids?

Ex Input:
Sexual reproduction results in offspring that are generally all genetically different.

Ex Output:
What kind of reproduction results in offspring that are generally all genetically different?