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: Coal is used to produce the movement of electrons by burning in coal-fire power stations. 
Question: Coal is used to produce the movement of electrons by what in coal-fire power stations?

Output: burning.


Input: Consider Input: Fact: Hot vapor makes the haze denser. 
Question: When does haze get denser?

Output: When the water is hot.


Input: Consider Input: Fact: gases released during the use of fossil fuels causes sea level rise. 
Question: What do fossil fuel gases cause?


Output: Sea level rise.