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.

[EX Q]: Question: Corals build hard exoskeletons that grow to become what? Answer: coral reefs
[EX A]: Corals build hard exoskeletons that grow to become coral reefs.

[EX Q]: Question: Urea and carbon dioxide are molecules with how many carbon atoms? Answer: one
[EX A]: Urea and carbon dioxide are molecules with one many carbon atoms.

[EX Q]: Question: What type of resource is limited in supply and cannot be replaced except over millions of years? Answer: natural resource
[EX A]:
Natural resource type of resource is limited in supply and cannot be replaced except over millions of years.