比如说：I don not know which room to live in ,什么时候加“in”

比如说：I don not know which room to live in ,什么时候加“in” I don't know which room i can live in.中in 省不省? There is not enough room for us to live in 为啥要加in 什么时候不加in呢? Which room we can not live in? can you tell me which room i can live in 为什么live后加in I don't think this room comfortable to live in. I don,t know which room i can live in这里为什么要用in O(∩_∩)O谢谢 I DO NOT HAVE A ROOM TO LIVE in对还是I DO NOT HAVE A ROOM TO LI I live in a room of which the window faces to the south.这句对吗 I live in a room __window opens to the south Aof which B who I want to live in a room which/that windows face the south.这 I live in a small room which ___(面向)south.