Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.
--------
Question: Question: What combines with rain to form acid rain? Answer: nitrogen and sulfur oxides

Answer: Courtesy of the U. S. EPA. Nitrogen and sulfur oxides combine with rain to form acid rain . Public Domain.

Question: Question: How can you calculate the density of matter? Answer: by dividing its mass by its volume

Answer: The density of matter can be calculated by dividing its mass by its volume.

Question: Question: Where do most red algae species live? Answer: oceans

Answer:
Red algae are a very large group of protists making up about 5,0006,000 species. They are mostly multicellular and live in the ocean. Many red algae are seaweeds and help create coral reefs.