选出正确答案. ( )(1)这是一张美国地图。 A. Here is a map of the United States. B. Here is the United States. ( )(2)这是美国的首都。 A. This is the capital city of the U.S. B. This is the United States. ( )(3)首都是华盛顿。 A. The city is Washington.,D. C. B. The capital city is Washington,D. C.