1. The perception associated with the amplitude of a sound wave is
A. timbre
B. loudness
C. tonal quality
D. richness
2. The structure that controls the size of the pupil is the
A. lens
B. iris
C. ciliary muscle
D. vitreous humor
3. Which of the following usually occurs in REM sleep
A. night terrors
B. nightmares
C. sleepwalking
D. enuresis