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.

[Q]: Fact: Scraping oneself on surfaces or things that have germs may cause infection. 
Question: Which of the following may cause infection?
[A]: Germy surfaces.


[Q]: Fact: the average number of individuals per unit of area affect the balance of the environment. 
Question: The average number of individuals per unit of area affect the balance of .?
[A]: the environment.


[Q]: Fact: Glucosamine sulphate is a basic building block for blood. 
Question: What is a basic building block for blood?
[A]:
glucosamine sulphate.