The long-ruling dictator of Mexico for much of the late-nineteenth and early-twentieth centuries was __________

President Rutherford B. Hayes’ order to withdraw federal troops from the South marked the end of

a. Reconstruction. b. segregation. c. slavery. d. the Black Codes. e. the Ku Klux Klan.

The double-blind control procedure is often used in what type of studies?

A) behavioral studies of weight management B) studies on autistic children C) drug studies D) studies concerned with effects of loss of eyesight