,一道填空是这样的 he came back late,（by） which time all the guests had already left
问题描述：
,一道填空是这样的 he came back late,（by） which time all the guests had already left
请问这是定语从句吗,如果是的话从句修饰的是那一部分?by which 代替的是主句里的哪一部分呢?还有which 前面为什么要接by呢
答
是定语从句,by “到.时为止”,which time 指代前面的他回来的时间,相当于 by the time when he came back,all the guests had already left.如果把 late 换成 at 10:00,可能好理解,但是 at 10:00 在句中也是作状语....