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.
--------
Question: Fact: bottom dwelling organisms can be filter feeders. 
Question: What can bottom dwelling organisms be?

Answer: filter feeders.


Question: Fact: Using hydropower reduces greenhouse gases. 
Question: What does hydropower help reduce?

Answer: Greenhouse gases.


Question: Fact: Cycles of freezing and thawing water cause something that can crack rocks. 
Question: What is created from cycles of freezing and thawing water?

Answer:
Something that cracks rocks.