问题补充：
The man was an old classmate of mine.
A. you just talked to him
B. who just talked to
C. you just talked to
D. whom you just talked
答案：
A. you just talked to him
B. who just talked to
(答案→)C. you just talked to
D. whom you just talked
解析：这要求一个定语从句(whom) you just talked to，其中关系代词whom用从句的to宾语，可以省略去。
