Which of these is NOT a primary pollutant?
A. Carbon monoxide
B. Carbon dioxide
C. Ground level ozone
D. Oxygen
Answer:D
Which of these is NOT a primary pollutant?
A. Carbon monoxide B. Carbon dioxide C. Ground level ozone D. Oxygen
Explanation: Ozone is not a primary pollutant since it is formed by the photo-chemical reaction of oxygen with the UV rays and not directly discharged into the atmosphere by a source.