Approximately what percent of American twelfth-graders smoke on a daily basis?

REM sleep refers to

a) dreamless sleep. b) sleep induced by sleeping pills. c) sleep periods in which sleepwalking is likely. d) sleep periods in which a person's eyes move rapidly.

Health officials generally believe that ________ should be the contraceptive of choice for adolescents

A) birth control pills B) condoms C) withdrawal D) the calendar method