D all of the above would be the correct answer
Answer:
Nitrogen is essential for all living things because it is a major part of amino acids, which are the building blocks of proteins and of nucleic acids such as DNA, which transfers genetic information to subsequent generations of organisms. hopes this helps let me know :)
A tornado, or twister.
Hope this helps ya :P
When oxygen is absent, anaerobic respiration occurs ('an' means without).