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: water flow through soil is variable. 
Question: What is the rate of water flow of soil?
variable.

Fact: individual nerve cells transmit nerve impulses to other cells. 
Question: What transmit nerve impulses to other cells?
individual nerve cells.

Fact: gases from burning coal and oil dissolving in water can harm plant life. 
Question: gases from burning coal and oil dissolving in water can harm what?

plant life.