定语从句中from where和 from which怎么区分

定语从句中引导词的选用主要看先行词在定语从句中作什么成分或者是定语从句中缺什么成分。

　　1．定语从句中缺主语，修饰人时用who /that，修饰物时用which /that引导。如：

　　is this the factory which /that makes tv sets？

　　the man who /that visited our school is from australia．

　　2．从句中缺宾语，修饰人时用 who /whom /that或省略引导词；修饰物时用which /that或省略引导词。如：

　　gone are the days which /that we spent together in the village．

　　he is the man who /whom /that i think to be worthy of our praise．

　　3．从句中缺时间状语，用when或介词+which引导。如：

　　the day finally came when /on which i was given a job．

　　we'll put off the outing until next week，when we won't be so busy．

　　4．从句中缺地点状语，用where或介词+which引导。如：

　　please put the letter on the desk where /on which he can easily find it．

　　5．从句中缺原因状语或先行词是 reason时，引导词用why /for which / that。如：

　　this is the reason why /for which / that he didn't come to the meeting．

　　6．从句中缺定语，人和物都用 whose引导。如：

　　a child whose parents are dead is called an orphan．

　　please pass me the dictionary whose cover is black．

　　7．当先行词是way时，其定语从句的引导词用in which /that。如：

　　the way in which /that he looks at problems is wrong．