Question

The president stood by a window inside the room, ____, looking over the square.

1. A.
   where I entered
2. B.
   into which I entered
3. C.
   which I entered
4. D.
   that I entered

Answer 1

C
 考查定语从句。Enter为及物动词，先行词the room为其宾语，不需使用介词，也不能用where。非限制性定语从句只能使用which。