Who devised the first age-graded scale to identify children needing special schooling by using tasks such as vocabulary, arithmetic, memory, discrimination, concpets, and comprehension questions?

Social smiles first appear ______________

a. within the first 2 weeks after birth b. in the second or third month c. later in the first year d. after 18 months

Survey research generally reveals that

a. most adolescents masturbate, but most adults do not b. most people with sexual partners masturbate c. most people who live alone masturbate, but most stop after they have a sexual partner d. as a general rule, only those people without sexual partners masturbate