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.

Fact: the platypus reproduces by laying eggs. 
Question: what reproduces by laying eggs?
platypus.

Fact: heating salt water leaves the salt on the surface. 
Question: heating salt water leaves the salt where?
on the surface.

Fact: Fireworks convert chemical energy into sound. 
Question: What do fireworks convert chemical energy into?

sound.