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.

Example Input: Fact: Fossil fuels can be formed by layers of sediment pushing down on decomposing algae. 
Question: What is a product of layers of sediment pushing down on decomposing algae over time?
Example Output: Fossil fuels.

Example Input: Fact: Flowers detect light and darkness. 
Question: What grows after detecting light?
Example Output: Flowers.

Example Input: Fact: Car engines usually use a fossil fuel to run. 
Question: What part of the car needs a fossil fuel to run?
Example Output:
Engine.