Andrew is an officer on a nuclear submarine that on occasion stays submerged for months, preventing any exposure to natural sunlight. To help maintain his normal sleeping habits, Andrew should
a. not worry about sleep, because his internal biological clocks can function perfectly in the absence of sunlight.
b. not try to go to sleep unless he can barely keep his eyes open.
c. nap for 15-20-minute intervals once per day.
d. maintain a regular schedule of eating and physical activity.
Question 2
The free-running daily cycle of human beings is _________ hours long.
a. between 22 and 23
b. between 23 and 24
c. between 24 and 25
d. more than 30
A mounted police officer in Poland
A partially submerged alligator displaying a typical ambush position
Nuclear medicine bone scan showing metastatic tumors in the skeleton
Deciduous and permanent teeth. (A) The deciduous teeth, with the age of eruption given in months; (B
The Chernobyl, Ukraine, Nuclear Power Plant Disaster
Children in Baltimore (1909) pull the stringy parts from beans in preparation for canning. Photograp