All areas of the brain shrink at the same rate

With the advent of condensed and evaporated milk in the late 1800s and its continuous growth in popularity in the United States, by 1940 what percent of mothers breast-fed their babies?

a. 10–20% b. 20–30% c. 30–40% d. 40–50%

Enrico, a five-month-old infant, begins to cry, and shortly thereafter, his mother appears, picks him up, and soothes him. Later, when Enrico is alone in his crib, he cries again. Enrico's latter crying episode is an example of a ___

a. reflex b. secondary circular reaction c. tertiary circular reaction d. mental representation