二、非限定性定语从句：非限定性定语从句的作用是对所修饰的成分作进一步说明，通常和主句间用逗号隔开，将从句拿掉后其他部分仍可成立
(一)which引导的非限定性定语从句来说明前面整个句子的情况或主句的某一部分(见第九章第一节、六、(六).)
(二)在引导限定性定语从句时，that有时相当于in which, at which, for which或at which
Attitudes towards daydreaming are changing in much the same way that(in which) attitudes towards night dreaming have changed. 人们对白日做梦的态度正在改变，这与人们对夜间做梦的看法的变化有非常相似之处。
I like the music for the very reason that(for which) he dislike it. 我出于某种原因喜欢这种音乐，而他恰恰与我相反。
We arrived the day that(on which) they left. 刚好我们到的那天他们走了。
(三)有时as也可用作关系代词(见第九章第一节、六、8.)
(四)在非限定性定语从句中，不能用that，而用who, whom代表人，用which代表事物
- Ligaments(韧带)， _____ ， hold organs of the body in place and fasten bones together．
［A］ which are fibrous tissues
［B］ they are fibrous tissues
［C］ fibrous tissues that
［D］ are fibrous tissues - The Little White House in Warm Springs was the Georgia home of President Franklin D. Roosevelt， _____ there on April 12， 1945．
［A］ who died
［B］ died
［C］ while died
［D］ he died - The first United States citizen to become ［A］ a professional ［B］ sculptor was Patience Lovell Wright， which ［C］ works were executed in wax ［D］ ．
