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

[EX Q]: Proteins are long chains of amino acids.
[EX A]: What are long chains of amino acids?

[EX Q]: Changing the shape of an elastic material gives it potential energy.
[EX A]: Changing the shape of an elastic material gives it what type of energy?

[EX Q]: We call the study of rock layers stratigraphy.
[EX A]:
What do we call the study of rock layers?