问题
选择题
—Is Bob still teaching?
—I’m afraid not. He is said the school as he has become a businessman.
A．that he has left
B．to leave
C．to have left
D．to be left
答案
答案：C
题目分析：根据“as he has become a businessman.”可判断出不定式动作leave发生在谓语动词表示的动作之前，故用不定式的完成时，故选C。
点评：不定式的完成式表示的动作发生在谓语动词表示的动作之前，强调动作的先后顺序。