A. HF
B. SO2
C. H2S
D. Both B. & C.
A. Use of silencers
B. Green house gases
C. Vibration damg
D. Tree plantation
A. Using the activities of bacteria and other micro organisms
B. Aerobic oxidation
C. Both A. & B.
D. Neither A. nor B.
A. Photochemical smog
B. Sulphur dioxide
C. Nitrogen dioxide
D. Dust particles
A. < 1
B. 10-100
C. 100-200
D. 100-1000
A. By reaction of hydrocarbon & nitric oxide in presence of sunlight
B. Appears only on sunny days
C. Is harmful for crops and trees also besides causing eye irritation & asthma
D. All A., B. & C.
A. 25
B. 50
C. 80
D. 120