What does the passage mainly discuss? A. The economic impact of air pollution. B. What constitutes an air pollutant. C. How much harm air pollutants can cause. D. The effects of compou
What does the passage mainly discuss?
A. The economic impact of air pollution.
B. What constitutes an air pollutant.
C. How much harm air pollutants can cause.
D. The effects of compounds added to the atmosphere.