Among older married couples, if one partner becomes seriously ill, that person's most likely caregiver is:

Without heroin, withdrawal symptoms begin to appear in:

A) 2 to 4 hours. B) 6 to 8 hours. C) 10 to 12 hours. D) 14 to 16 hours.

Experimental designs that expose subjects to more than one treatment condition each are referred to as

a. expectancy control designs. b. repeated-measures designs. c. nested designs. d. between-subjects designs.