第二部分：英语知识运用（共两节，满分45分）
第一节 单项填空（共15小题，每小题1分，满分15分）
21. Appointed as _____ ambassador to the UN, he was determined to serve his country _____ heart and soul.

A．/; /

B．the; the

C．an; the

D．the; a