You are presented with the quiz "What is  found naturally in the air and soil, and in living organisms?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "nitrogen is found in proteins, nucleic acids, and chlorophyll" and "large amounts of nitrogen are found naturally in the air and soil, and in living organisms". 

So, what's the best answer to the question?


 

    protein,nucleic acid,chlorophy       