I often watch CCTV-9 I have learned a lot of new words and expressions.A. from whichB.

问题补充：

I often watch CCTV-9, I have learned a lot of new words and expressions.

A. from which

B. of which

C. to which

D. which

答案：

(答案→)A. from which

B. of which

C. to which

D. which

解析：考查非限制性定语从句。“从......学到......”learn sth. from ...；“我经常看中央9频道，我已经从中央9套学到了很多新词和短语。”根据介词from排除B、C、D。故选A。