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: Repellents can stop harm caused by flea bites. 
Question: How can you prevent harm caused by flea bites?
answer:
Using repellent.


question:
Fact: a source of nutrients consists of organic molecules that store energy in their chemical bonds. 
Question: What consists of organic molecules that store energy in their chemical bonds?
answer:
source of nutrients.


question:
Fact: Antibodies bind to allergens. 
Question: _ bind to allergens.?
answer:

Antibodies.