In a study, the subjects do not know to which group they are assigned, but the researchers are aware of the subjects’ group assignments.

a. double-blind
b. placebo
c. single-blind
d. control

Which statement best describes a major advantage of a confederal system of government over a unitary system

Which kingdom once merged with egypt? a. nubiab. bantuc. phoeniciad. babylon

Plz where was the inca civilization located? a. in and around the andes mountains of south america. b. central america in southern mexico. c. the caribbean islands. d. the central valley of mexico.