How do humans obtain the nitrogen they ues in their bodies

Explanation:

The most common form of nitrogen in your body is proteins containing mainly carbon, hydrogen, oxygen and nitrogen. While neither humans nor animals can get nitrogen into their bodies from the air or soil, they do gain nitrogen from vegetation or other animals which eat vegetation.

answer; i believe the correct answer is ( proteins );

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.