In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

[Q]: Question: What type of energy travels through matter in wave form? Answer: sound
[A]: Sound energy travels through matter in wave form.

[Q]: Question: Which of these can be mined from Earth and used as an energy source? Answer: Coal
[A]: Coal can be mined from earth and used as an energy source.

[Q]: Question: Lying with their mouths open, a behavior called gaping, probably serves what function for crocodiles? Answer: cooling down
[A]:
Lying with their mouths open, a behavior called gaping, probably serves the function of cooling down for crocodiles.