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.

Fact: Breathing provides one substance transported by the blood. 
Question: What process provides one substance transported by the blood?
breathing.

Fact: expansion can cause fatigue. 
Question: what can cause fatigue?
expansion.

Fact: the Earth revolving around the Sun causes winter. 
Question: What is a cause of the Earth revolving around the Sun?

winter.