Which of the following is the most active zone of atmosphere in which weathering events like rain, storm & lightning occur ?

A. Deaeration of feed water
B. Enhancing pH of feed water by adding alkali
C. Feeding sodium sulphite or hydrazine phosphate to the boilers, which combines with oxygen
and prevents corrosion
D. All A., B. and C.

A. Natural aeration of water stream
B. Photosynthetic action of algae
C. Both A. & B.
D. Neither A. nor B.

A. Stratosphere
B. Troposphere
C. Ionosphere
D. None of these

A. Cancer
B. Silicosis
C. Respiratory disease (e.g., asthma)
D. Reduced crop yield

A. Paralysis of muscles & loss of appetite
B. Nervous depression
C. Gastritis and diarrhea
D. All A., B. and C.

A. Automobile exhaust
B. Blanketing effect of CO2 in the atmosphere
C. De-forestation
D. Thickening of ozone layer