This book is written by my sister is working for CCTV.A. sheB. thatC. whomD. who

问题补充：

This book is written by my sister, is working for CCTV.

A. she

B. that

C. whom

D. who

答案：

A. she

B. that

C. whom

(答案→)D. who

解析：考查定语从句。my sister是先行词，从句 is working for CCTV.缺主语，且指人，选D。