The common features between NO2, SO2, CO2 and SPM is that all of them___________
A. Are classified as primary pollutants.
B. Are classified as secondary pollutants.
C. Have equal role in causing acid rain.
D. Are greenhouse gases.
Answer:A
The common features between NO2, SO2, CO2 and SPM is that all of them___________
A. Are classified as primary pollutants. B. Are classified as secondary pollutants. C. Have equal role in causing acid rain. D. Are greenhouse gases.