问题补充：
The United States fifty states , one of which is separated from the others by the Pacific Ocean.
A. consists of
B. is consisted of
C. are made up of
D. makes up
答案：
(答案→)A. consists of
B. is consisted of
C. are made up of
D. makes up
解析：考查固定短语和主谓一致。The United States作主语时，谓语动词要用单数，排除C; consist of由……构成，无被动，排除B；make up构成……，与句意不符。所以选A。
