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_________.