All of the following are examples of methods used to protect computers EXCEPT ________.

A normal QRS complex is:

a. < 0.12 seconds. b. 1.2–2.0 seconds. c. > 0.12 seconds. d. >1 second.

Typical stroke volume is about ________ of the volume of the left ventricle

A) one-third B) one-half C) two-thirds D) three-quarters