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: Smog is an airborne pollutant. 
Question: What is an airborne pollutant?
[EX A]: Smog.

[EX Q]: Fact: Veins generally carry blue blood. 
Question: Veins generally carry what type of blood?
[EX A]: blue.

[EX Q]: Fact: Cells are the microscopic building blocks of living beings. 
Question: What is the microscopic building block of any living being?
[EX A]:
cell.