Which amendment to the Constitution abolished slavery?

According to the introduction, the main difference between domestic and international politics is

a. that domestic politics is more anarchic. b. that international politics involves more violence. c. that international politics is more difficult to understand. d. that domestic politics is more complex than international politics. e. that unlike domestic politics, international politics takes place in an arena with no central governing authority.

A case which is less than the mean has a z-score which is:

a. negative b. non-existent c. valueless d. none of the above