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: amoebae have motility. 
Question: what have motility?
[EX A]: amoebae.

[EX Q]: Fact: if a pine falls then sunlight becomes available to the surrounding plants. 
Question: what provides more sunlight to surrounding plants by falling?
[EX A]: pine.

[EX Q]: Fact: Volcanic clouds in the atmosphere is a particular problem for aircraft. 
Question: What are particular problems for aircraft in the atmosphere?
[EX A]:
volcanic clouds.