According to the third paragraph, which of the following statements is NOT TRUE? A. Our social life has no influence on our hours of sleep. B. The sun obviously determined our daily routin
According to the third paragraph, which of the following statements is NOT TRUE?
A. Our social life has no influence on our hours of sleep.
B. The sun obviously determined our daily routines.
C. The electric light was invented in the 19th century.
D. The electric light has changed our daily cycle of sleep.