Which approach to psychotherapy that arose in the 20th century emphasized empirical methodology and the study and treatment of measurable, observable symptoms?

When a new mobile is first hung over baby Jessica's crib, she looks at it frequently, but after several weeks pass she hardly notices it. Jessica has become ________ to the mobile.

a. classically conditioned b. operantly conditioned c. habituated d. counterconditioned

Receptor cells in the retina responsible for night vision are __________

a) bipolar cells. b) ganglion cells. c) rods. d) cones.