Nitrogen in the atmosphere must be “fixed” before it can be used by plants. atmospheric nitrogen is “fixed” by

D)bacteria and lightning.

Explanation:

According to USA Testprep (Where the question came from), "Nitrogen is fixed or chemically combined with other elements to form a usable chemical compound. Plants are then able to use nitrogen in this form; they are not able to use it in its atmospheric form." I hope this helps those that try to find the answer.

it is a

explanation:

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.