If a woman keeps track of her menstrual cycles and finds that the shortest was 24 days and the longest was 32 days, what is the fertile (unsafe) period to avoid sexual intercourse according to the calendar method?

The presence of a drug tolerance and withdrawal symptoms is indicative of

a. polydrug abuse. b. a physical dependence. c. an emotional dependence. d. a psychological dependence.

Harlow's studies with the two artificial mothers concluded that

A. infant monkeys were motivated by the need for contact and comfort. B. females isolated at birth from all social contact still develop into good mothers. C. infant monkeys are more attached to caregivers who provide food than to caregivers who provide comfort. D. monkeys were able to successfully overcome maternal separation and being socially isolated for years.