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: pines have a positive impact on an ecosystem. 
Question: what has a positive impact on an ecosystem?

Output: pines.


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: heat and pressure changes fossils into fossil fuel. 
Question: Heat and pressure upon fossils creates what?


Output: fossil fuels.