Question

do you know... they are talking about

-Do you know the things and persons______ they are talking about？（　　）

A. which

B. who

C. whom

D. that

Answer 1

答案 D．
首先分析句子结构，本句中的"______ they are talking about"在复合句中作定语从句，由于先行词 the things and persons是并列结构，既有人又有物，因而定语从句只能用that来引导，不能用which．故选D．