一般介词＋关系词，譬如on which，in which都是做定语从句中的副词，也就是状语，那样这个which除去做前面介词的宾语，是不是还能做从句的主语或宾语呢？
譬如句子：you can sign in the full text in any journals towhich your institution subscribes to.
which既充当to的介词宾语，又充当后面subscribs to的介词宾语，如此能否呢？
You can sign in the full text in any journals to which your institution subscribes to. （错误）
You can sign in the full text in any journals which your institution subscribes to. （正确）
You can sign in the full text in any journals to which your institution subscribes .（正确）
