In an adult, at what angle does the left mainstem bronchus branch from the trachea?

Automaticity is the ability of cardiac pacemaker cells to:

A. generate their own impulses without external stimulation. B. respond to an electrical stimulus. C. receive an electrical impulse. D. cause cardiac muscle contraction.

Maximum charge a plan pays for a service or procedure may be referred to as

A. allowed amount. B. allowed charge. C. maximum allowable fee. D. all of these are correct.