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: Each starfish arm contains part of the water vascular system. 
Question: Where does a starfish have its water vascular system?
in its arms.

Fact: Cars damage the environment by causing an excess of contaminants. 
Question: How do cars damage the environment?
Emitting an excess of contaminants.

Fact: Insects sometimes change population size by moving from one place to another. 
Question: When insects move from one place to another, this usually causes?

change in population size.