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.

Input: Consider Input: Fact: comparators, flats, and microscopes could be used for observing materials up close. 
Question: comparators, flats, and microscopes could be used for observing materials how?

Output: up close.


Input: Consider Input: Fact: Hydrogen bonds cause H20 to expand when it freezes. 
Question: What causes H20 to expand when frozen?

Output: hydrogen bonds.


Input: Consider Input: Fact: Cell walls relax and increase the flow of blood. 
Question: Cell walls relax and increase the flow of what?


Output: blood.