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: most animals consume and are consumed by more than one species. 
Question: what consume and are consumed by more than one species?
animals.

Fact: A person's elbow straightens when muscles antagonistic to biceps contract. 
Question: A person's elbow straightens when muscles antagonistic to what contract?
biceps.

Fact: Increasing the density of water decreases its melting point. 
Question: What decreases the melting point of water?

increasing its density.