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: marine and benthic creatures lack respiratory and excretory systems. 
Question: what creatures lack respiratory and excretory systems?
Example Output: marine and benthic.

Example Input: Fact: Toyota causes pollution. 
Question: What causes pollution?
Example Output: Toyota.

Example Input: Fact: microbial fuel cells convert food into electrical energy. 
Question: What converts food into electrical energy?
Example Output:
microbial fuel cells.