My father and his teacher talked for about an hour of things and persons they remembered

问题补充：

My father and his teacher talked for about an hour of things and persons they remembered at the school.

A. that

B. which

C. who

D. what

答案：

(答案→)A. that

B. which

C. who

D. what

解析：考查定语从句。先行词有人也有物的时候，用关系代词that。