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: Starfish lack respiratory and excretory systems. 
Question: What is an example of an animal that lacks a respiratory and excretory system?

A: Starfish.
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Q: Fact: if a gas is heated the density decreases. 
Question: What happens to the density of a gas when heated?

A: decreases.
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Q: Fact: Sexual reproduction creates evolution. 
Question: What creates evolution?

A:
Sexual reproduction.
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