单项选择题
The serious economic crisis in the late 1920s and 1930s first brought about by（）
A.bank failures B.serious unemployment C.farm foreclosures D.the stock market crash
单项选择题 One of the serious weaknesses in American economy in the 1920s was（）
单项选择题 Sacco and Vanzetti were sentenced to death and executed because（）
单项选择题 typically represented the world pattern between the two world wars（）
