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.

[Q]: Fact: Absorbing energy causes metal objects to expand. 
Question: Metal expands when it does what?
[A]: absorbs energy.


[Q]: Fact: a drug that can be addictive is an example of a psychoactive drug. 
Question: a drug that can be addictive is an example of a what?
[A]: psychoactive drug.


[Q]: Fact: Adult urochordates are barrel-shaped. 
Question: Adult urochordates are _-shaped.?
[A]:
barrel.