instruction:
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.
question:
Fact: certain Steel products have a positive impact on the environment. 
Question: certain Steel products have a positive impact on what?
answer:
environment.


question:
Fact: animals use glucose for energy. 
Question: what do animals use for energy?
answer:
glucose.


question:
Fact: heat or cold can cause phase changes. 
Question: What can cause phase changes?
answer:

heat or cold.