What are some benifits with being a doctor?

Darren was recently ticketed for speeding over 110 mph on the freeway. when the police officer stopped darren and asked him why he was going so fast, he replied that he was "king of the world." the month before this, darren felt sad and listless and had trouble getting up the energy to go to school. he probably suffers from:

Cardiovascular efficiency, muscular strength and endurance, flexibility, and body composition are all related factors.

How does nitrogen oxides are produced and their air environment impact