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: air is required for breathing. 
Question: What is required for breathing?

Answer: air.


Question: Fact: erosion forms canyons. 
Question: What are formed by erosion?

Answer: canyons.


Question: Fact: Earthworms ingest sediment to then help form and enrich soil. 
Question: What do earthworms ingest in order to form and enrich soil?

Answer:
sediment.