Professor Haley told me that heby many of his students at the railway station.A. had been

问题补充：

Professor Haley told me that heby many of his students at the railway station.

A. had been seen off

B. have been seen off

C. had seen off

D. have seen off

答案：

(答案→)A. had been seen off

B. have been seen off

C. had seen off

D. have seen off

解析：学生为Haley教授送行的事实发生在他告诉我之前,故而要用过去完成时。