engineering recuitment HPCL Engineer Mock Test 2024 People Development & Environment Basics of Environment
According to UNEP, which of the following is/are the major component/s of air pollution?
1. SO2
2. O3
3. CO
4. NO2
Select the correct answer using the code given below :
1
2 and 3 only
2
2 only
3
2, 3 and 4 only
4
1, 2, 3 and 4