About ________ of the population experience insomnia as a persistent problem while ________ experience insomnia on an occasion.
A) 1 percent; 3 percent
B) 15 percent; 52 percent
C) 27 percent; 45 percent
D) 7 percent; 19 percent
E) 9 percent; 25 percent
Question 2
Which of the following is true of the sleep cycle during a night of sleep?
A) Each non-REM/REM cycle lasts about 45 minutes.
B) Subjects first enter REM sleep and then transition to non-REM sleep.
C) As the night goes on, the relative length of REM sleep increases in each successive cycle.
D) Stages 3 and 4 of slow-wave sleep mostly occur in the early morning hours.
E) Sleep cycles are random across the night.