Nitrogen Is Often in Short Supply in Terrestrial Ecosystems Because

Multiple Choice

Nitrogen is often in short supply in terrestrial ecosystems because

A) there is very little free nitrogen in the air.
B) most organisms cannot use atmospheric nitrogen.
C) there are frequent local shortages of atmospheric nitrogen.
D) nitrogen enters cells slowly because of its low solubility in water.
E) atmospheric nitrogen seldom comes into contact with terrestrial ecosystems.