Smoke, fumes, ash, dust, nitric oxide and sulphur dioxide are the main sources of ________.
A. Primary Pollutants
B. Secondary pollutants
C. Bio-Degradable Pollutants
D. None of the above
Answer:A
Smoke, fumes, ash, dust, nitric oxide and sulphur dioxide are the main sources of ________.
A. Primary Pollutants B. Secondary pollutants C. Bio-Degradable Pollutants D. None of the above