Write a correct answer to the given question based on its associated fact. Make sure that your answer is contained in the associated fact. Don't be creative and introduce any new word that is not mentioned in the associated fact! Remember that the associated fact has been rearranged to form the question. So, the correct answer words must lie within the associated fact. The correct answer can be a word, phrase, or even a sentence.

[EX Q]: Fact: An item's weight causes its gravitational force. 
Question: The weight of an item causes its what?
[EX A]: gravitational weight.

[EX Q]: Fact: Heating with coal can cause air pollution. 
Question: Heating with coal can cause?
[EX A]: air pollution.

[EX Q]: Fact: Communities consist of populations of different groups that produce fertile offspring. 
Question: Communities consist of populations of different groups that do what?
[EX A]:
Produce fertile offspring.