instruction:
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: navigation requires knowing which way to go. 
Question: What requires knowing which way to go?
answer:
navigation.


question:
Fact: The things that are the smallest agents of disease are usually considered to be nonliving. 
Question: The things that are the smallest agents of disease are usually considered to be what?
answer:
nonliving.


question:
Fact: harming an animal species has a negative impact on the number of individuals in that species. 
Question: Harming an animal species has a negative impact on what?
answer:

The number of individuals.