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: Hot vapor makes the haze denser. 
Question: When does haze get denser?
[EX A]: When the water is hot.

[EX Q]: Fact: Starfish lack respiratory and excretory systems. 
Question: What kind of animal doesn't have a respiratory or excretory system?
[EX A]: starfish.

[EX Q]: Fact: Animals in class aves move their wings using muscles in the chest. 
Question: What kind of animals are able to move their wings by moving muscles in their chest?
[EX A]:
animals in Class Aves.