The way a drug is administered has little or no impact on its addictive potential--it is all about the nature of the substance that is used.

The fertilized egg will develop into a boy if, at conception,

a. the sperm contributes an X chromosome. b. the sperm contributes a Y chromosome. c. the egg contributes an X chromosome. d. the egg contributes a Y chromosome.

If these lines, _______________, were seen as one long line, this would be an example of the Gestalt principle of

A) proximity. B) closure. C) continuity. D) symmetry.