Obama has been elected first black President of the United States and the international

问题补充：

Obama has been elected first black President of the United States, and the international society expects to have new USA under his leadership.

A. /；the

B. a；the

C. the；a

D. the；the

答案：

A. /；the

B. a；the

(答案→)C. the；a

D. the；the

解析：第一个空表示顺序，所以序数词first前应填定冠词the，第二个空表示地点的专有名词USA前有形容词new修饰，故用不定冠词来限定。