The nitrogen molecules present in air can be converted into nitrates and nitrites by
A. a biological process of nitrogen fixing bacteria present in soil
B. a biological process of carbon fixing factor present in soil
C. any of the industries manufacturing nitrogenous compounds
D. the plants used as cereal crops in field
Answer:A
The nitrogen molecules present in air can be converted into nitrates and nitrites by
A. a biological process of nitrogen fixing bacteria present in soil B. a biological process of carbon fixing factor present in soil C. any of the industries manufacturing nitrogenous compounds D. the plants used as cereal crops in field