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.

Example Input: Fact: thirst is used to make an animal realize that it needs to replenish H2O in its body. 
Question: Thirst shows an animal that it needs what?
Example Output: H2O.

Example Input: Fact: if members of a species cannot mate with females then that species will likely become extinct. 
Question: if members of a species cannot what, then that species will likely become extinct?
Example Output: mate with females.

Example Input: Fact: Snails and slugs lack a backbone. 
Question: what do snails and slugs lack?
Example Output:
a backbone.