Which part of the cardiac conduction system is known as the pacemaker of the heart? 

What is the appropriate method for delivering a sterile item to the back table from a peel package?

a. Open peel pack away from self, using top flap to cover hand and arm; open item over center of back table. b. Open package laterally, and carefully slide item over glued edge onto top of back table. c. Open package toward self; then project item into air, aiming for back table. d. Open package laterally and completely; gently toss item without touching glued edge or going over back table.

The third molar's location of the distal contact area is:

A. middle third B. occlusal third C. middle of tooth D. 2/3 from the cervical line