There were 20 people sitting in the room half were women.A. of whomB. of whichC. about t

问题补充：

There were 20 people sitting in the room, half were women.

A. of whom

B. of which

C. about that

D. about whom

答案：

(答案→)A. of whom

B. of which

C. about that

D. about whom

解析：whom的先行词是people,此处填介词+ which ,指人时不用which .