36.There have been__________ periods in the development of American political parties in
the United States.
A. two B. three
C. four D. five
37.The 1920s in the United States has been described by many historians as a period of
___________.
A. material failure B. spiritual frustration
C. political setbacks D. welfare reform
38.___________is the largest single source of goods imported by the U.S.，accounting for nearly
30％of the total.
A. Canada B. Mexico
C. Japan D. European Union
39.Mark Twain’s masterwork was ___________ .
A. The Scarlet Letter B. Leaves of Grass
C. The Sketch Book D. The Adventures of Huckleberry Finn
40.In the early part of the 19th century，___________was the center of American writing.
A. Boston B. Philadelphia
C. Chicago D. New York City
