代替地點的關係副詞 where
http://www.learnerhall.org/2012/10/where.html
關係副詞 = 介係詞 + which
例：這就是他被謀殺的那間房間。
✓ 未使用關代連接兩句時
❶ This is the room.
❷ He was murdered in the room.
✓ 使用關係代名詞連接兩句
This is the room which he was murdered in.
= This is the room in which he was murdered.
= This is the room in which he was murdered.
✓ 改成代替地點的關係副詞
This is the room where he was murdered.
代替地點 ( the room ) 的關係副詞 where = in + which
