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: Irradiating food can be used to kill something that causes fermentation in the food. 
Question: Irradiating food can be used to kill what in the food?
[EX A]: Something that causes fermentation.

[EX Q]: Fact: molds have special structures for penetrating a host. 
Question: What has special structures for penetrating a host?
[EX A]: molds.

[EX Q]: Fact: condensation in clouds is similar to humidity in the air. 
Question: condensation in the air and humidity are caused by?
[EX A]:
water.