选择以下的句子补全对话
A.Thank you very much.
B.No,it isn't.
C.Where is it?
D.Is it under the table?
E.Yes,it is.
1.I can't find my backpack.
2.Don't worry.________
3.___________
4.Is it on the dresser?
5.No,it isn't.
6.Ah,I find your backpack.
7._________
8.It is on your back,but you don't know.
9.Ah,______ _________