1、隻用which不用that的情況。
2、引導非限制性定語從句時。例如：Bamboo is hollow, which makes it light.竹子是空心的，這使得他很輕。
3、當關系詞前有介詞時。例如：This is the room in which Chairman Mao once lived.這就是毛主席曾經住過的地方。
4、在一個句子中有兩個定語從句，其中一個定語從句的關系代詞用了that，另一個宜用which.例如：Let me show you the novel that I borrowed from the library which was newly open to us.我來給你看我從新開的圖書館裡借來的那本小說。
5、當關系代詞後面有插入語時。例如：Here is the English grammar which, as I have told you, will help improve your English.這就是我跟你說過的會有助于你學好英語的那本英語語法書。
6、先行詞為that時。例如：The clock is that which can tell us the time.鐘是報時的裝置。
zpostcode 
Recruit 
weather 
mreligion 
Yellowpages 
sport 
constellation 
shopping 
name 
game 
directory 
literature 
Word 
tour 
furnish 
Lottery 
tftnews 
lyrics 
News 
digital 
car 
dir 
Edu 
Finance 
