Most children begin to point at objects by the time they are how many months old?

Biological drives are

a. learned. b. unlearned. c. produced by external incentives. d. exceptions to the drive-reduction principle. e. the same as instincts.

People are to __________ selection as nature is to __________ selection

a. regressive; progressive b. environmental; genetic c. artificial; natural d. supportive; adaptive