Since the ratification of the Seventeenth Amendment in _____, members of both houses of Congress have been directly elected.
A、1870
B、1918
C、1960
D、1913
【正确答案】：D
【题目解析】：
答案选D。Since the ratification of the Seventeenth Amendment in 1913, members of both houses of Congress have been directly elected.参见教材P246。
