专四语法：PART4 定语从句

i will never forget the day on which i joined the youth league. （on which = when, 表示在具体某一天介词用on）

2、介词与定语从句中的动词词组是一种习惯性搭配。例如：

here comes the kind professor to whom we often turn for help. （turn to sb for help）

who is the young woman with whom our headmaster is shaking hands? （shake hands with sb）

3、介词与定语从句中的形容词短语是一种习惯性搭配。