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.

[EX Q]: Fact: food is irradiated for space travel. 
Question: what food is required for space travel?
[EX A]: irradiated.

[EX Q]: Fact: the platypus reproduces by laying eggs. 
Question: what reproduces by laying eggs?
[EX A]: platypus.

[EX Q]: Fact: A disease in which osteoclasts are more active than osteoblasts decreases bone density. 
Question: How does a disease in which osteoclasts are more active than osteoblasts affect bone density.?
[EX A]:
decreases it.