19.They talked about things and persons they remembered in the school.A. whoB. whichC. th

问题补充：

19.They talked about things and persons they remembered in the school.

A. who

B. which

C. that

D. what

答案：

A. who

B. which

(答案→)C. that

D. what

解析：定语从句中先行词有“人”和“物”时，关系代词that不能省略。