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: parasites can cause harmful diseases. 
Question: certain diseases can be caused by what?
[A]: parasites.


[Q]: Fact: incinerated mercury can cause the ph of soil to decrease. 
Question: what can cause the ph of soil to decrease?
[A]: incinerated mercury.


[Q]: Fact: pushing with strokes on a bike cause that bike to move. 
Question: pushing with strokes on a bike cause that bike to what?
[A]:
move.