According to recent research, the percentage of people age 18 to 23 who have already experienced major depression is _____ percent

Female breasts are to ________ as male testes are to ________.

A. menarche; menopause B. menopause; menarche C. secondary sex characteristics; primary sex characteristics D. primary sex characteristics; secondary sex characteristics

Maxine is currently sleeping. She is continuing to experience delta waves and she is very hard to rouse. Maxine is in __________ sleep

A) Stage 1 B) Stage 2 C) Stage 4 D) REM