A common source of acid rain is air pollution that contains sulfur. This creates sulfuric acid when it mixes with water vapor in the air. Sulfur air pollution is easy to identify because it has a rotten-egg odor. What are some sources of sulfur air pollution you have encountered?

What is a population? a. all the members of the same species living in the same ecosystem at the same time b. the number of a species living in the same ecosystem over a period of time c. the total number of organisms living in an ecosystem at a point in time d. all the members of a food web in the same ecosystem