单选题 The firm has seen considerable changes after he ______ to be the director of the business division.
A. elect
B. to elect
C. was elected
D. elected

【正确答案】 C

【答案解析】中级问题空格内应填入谓语动词，并和after(连词)后的主语he搭配。首先排除B选项；因为应填入动词的单数形式，排除A选项；C选项和D选项则是主动语态和被动语态的区分。空格后没有可以做宾语的名词，因此选择被动语态，是elect him (to be) the director的被动形式。