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: most bigger cities require vehicles. 
Question: What do most bigger cities require?

Answer: vehicles.


Question: Fact: hormones control heart rate. 
Question: What do hormones control?

Answer: Heart rate.


Question: Fact: pollinators are naturalized on every continent except Antarctica. 
Question: What are naturalized on every continent except Antarctica?

Answer:
pollinators.