题干
---- My key is gone．Have you seen it anywhere?
---- Oh, it is in the room ______ we had a talk last night．
---- Oh, it is in the room ______ we had a talk last night．
A：that
B：which
C：where
D：what
答案(点此获取答案解析）
C
的定义域是
,则实数
的取值范围是（ ）