阅读下面这段对话，完成文后任务。
Miss Huang: Morning, class.
Pupils: Morning, Miss Huang.
Miss Huang: OK. Bob, what's this?
Bob: It's a dog. (A)
Miss Huang: Good. What's this room, Grace?
Grace: I don't know (我
不知道).
Alice: I know. (B)
Miss Huang: Good .(C)
Alice: A sun.
Miss Huang: Is this a classroom?
Alice: Yes, it is.(D)
Miss Huang: What is it, Dale?
Dale: It's a music room.
1. Morning 是_________更为口语化的表达形式。
2.句子 It's a lab.应还原到对话中的_________处。
3. 句子What's this?应还原到对话中的_________处。
4. _________ is a teacher (老师)。
5. Dale is a_________.