Mary lives in the room.the door ____ opens east.
问题描述：
Mary lives in the room.the door ____ opens east.
A.of it B.of which C.of that D.whose
Which one?Why?
答
B.of which看如下两个分句：Mary lives in the room.the door _of the room_ opens east.把两句合成一句复合句：Mary lives in the room,whose door opens east.Mary lives in the room,the door of which opens eas...