2016年职称英语备考：定语从句
句型1：
由as引导的非限定性的定语从句。如：
As we have known,he is a most good student.众所周知，他是个很好的学生。请比较：It is well-known that he is a most good student.（前一个是定语从句，而后者是个主语从句。)
句型2：
由which引导的非限定性的定语从句。如：
He is a professor,which I have been looking forward to becoming. 他是个教授，那是我一直盼望的职业。（因为先行词professor是表示职业的名词，因此引导词用which，而不用who。
句型3：
由where,when引导的定语从句（其中包括限定性的或非限定性的。)如：
This is the house where I used to come.请比较：This is the house which /that I used to come to.
This is the day when I joined the Party.请比较：This is the day which /that I joined the Party on.
（说明：关于that与which之间的区别，请看关系代词that和which的区别。)
