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.

Input: Consider Input: Fact: Mammals can generate little bursts of energy by shivering. 
Question: What can a mammal produce by shivering?

Output: energy.


Input: Consider Input: Fact: Hummingbirds co-evolved with plants. 
Question: Hummingbirds are what they are today as a necessary consequence of their relationship to what?

Output: Plants.


Input: Consider Input: Fact: Sonar is used to find the position of objects. 
Question: What can be used to find the position of objects?


Output: Sonar.