What is the medication that can reverse benzodiazepine overdoses, but can also precipitate seizures?

Shock can best be described as:

A) hypotension. B) a decrease in myocardial contractility. C) decreased cardiac output. D) a state of inadequate tissue perfusion.

When blood is centrifuged, the heavier red blood cells move to one end of the tube, lighter plasma moves to the other end, and the ________ ________ that contains the white blood cells and platelets is between the two. 

Fill in the blank(s) with the appropriate word(s).