英语翻译This is the house in which Lu Xun lived.

这句话拆成两句你就懂了:
This is the house.
Lu Xun lived in this house.
在第二句里面,用which代替了相同部分this house,所以就成了This is the house in which Lu Xun lived.

这是鲁迅住过的的房子。
其中 in which是代替的where，做状语，如for what可以代替why。其中in和which不可拆开看。句子也可以改为This is the house which Lu Xun lived in。或This is the house where Lu Xun lived.关键是live后是接in

这就是鲁迅住的房子。this is the house which Luxun lived in.which 引导的定语从句which 做live in 中in 的宾语