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: animals use sound to find a mate. 
Question: What do animals use to find a mate?
[EX A]: sound.

[EX Q]: Fact: Fungi can not absorb light energy. 
Question: What can fungi not do?
[EX A]: absorb light energy.

[EX Q]: Fact: When the seasons change from the summer to the fall, symptoms of some depressive illnesses worsen. 
Question: When the seasons change from the summer to the fall, symptoms of what will sometimes worsen?
[EX A]:
depressive illnesses.