有关定语从句用法问题，积极回答呦~~

分析：

介词+which
这类从句中介词的选择与句子的其它成份密切相关，要依据其搭配设当选择. 如：

（1）I called him by the wrong name ,for which mistake I should apologize 本句用for 是因为apologize for...这个短语，也可将for 放在后面，即本句可改为：I called him by the wrong name ,which mistake I should apologize for

（2）We went through a period in which communications were very difficult in the rural areas. 本句用in是因为in the period 但是不要误以为句子后面已经有in了，这样用重复了，仔细观察可以发现，句子后面的in是和 the rural areas打搭配的，不要混淆。把从句补充完整communications were very difficult in the rural areas in the period。

当然还有很多很多介词可以和which这样连用，如：
We saw several natives advancing towards our party, and one of them came up to us, to whom we gave some bells and glasses.

He was educated at the local high school,after which he went on to Beijing University.

请你做一下题练习一下吧：
1. I have many friends ,______ some are businessmen .

A．of them B．from which C．who of D. of whom

2. Mark was a student