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.