Cross-Cultural Research Has Shown That,in Most Cultures Studied

Cross-cultural research has shown that,in most cultures studied,

A) those with a written language have the lowest rates of masturbation.
B) sexual intercourse occurs most often when couples awaken in the morning.
C) foreplay precedes sexual intercourse.
D) the percent of females experiencing regular orgasms is fairly constant.
E) women usually initiate foreplay.