There is a period of sleep during which the brain is very active, voluntary muscle activity becomes suppressed, physiological arousal is considerable, and the eyes move back and forth under closed eyelids. this period is called:

REM sleep

Explanation:

REM sleep is the period of sleep during which the brain is very active, voluntary muscle activity becomes suppressed, there is considerable physiological arousal, and one's eyes move back and forth under closed eyelids. Dreaming consistently occurs.

c. taught scientists many new things about the earth, but not other planets.

explanation:

answer; proximity;