instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Changing the shape of an elastic material gives it potential energy.
answer:
Changing the shape of an elastic material gives it what type of energy?

question:
Renewable energy sources emit fewer or no greenhouse gases.
answer:
What type energy sources emit fewer or no greenhouse gases?

question:
Form a protective layer do heavy alkanes affect the skin.
answer:
How do heavy alkanes affect the skin?