The World Health Organization directed the research that resulted in a vaccine that ended smallpox

Matched-subjects designs are commonly used when

A) we need an independent-subjects group. B) researchers are studying eye color or visual acuity. C) several dependent variables are being tested at the same time. D) exposure to a condition causes long-term changes in the participant, making it impossible for the participant to appear in the other conditions.

Since the last decades of the twentieth century, Republicans have drawn large numbers of

a. Hispanic Catholic voters. b. Jewish voters. c. very religious white voters. d. non-religious white voters. e. non-religious minority voters.