According to the first national census, in 1790, about ____ percent of the American population lived in slavery.

In the 1970s, authoritarian regimes ruled how much of the world?

A. 90% B. 40% C. 50% D. 75%

______ refers to the sum total of the use of taxing and spending by the federal government.

Fill in the blank(s) with the appropriate word(s).