选择下面的句子补全对话：

　　A．He gives it to Miss Gao.

　　B．Let me help him clean the classroom.

　　C．But he isn't here.

　　D．Let's go home.

　　E．It's time to go home.

　　F．I'm on duty today.

　　G．What's the time, please?

　　H．He's in the teacher's room.

　　I．He's a very good boy.

　　J．Is Li Lei on duty today?

　　Liu Tong: Excuse me, (1) ?

　　Hu Cheng: It's five o'clock. (2) .

　　Liu Tong: Yes.

　　Hu Cheng: (3) !

　　Liu Tong: Oh, no. (4) . I must clean our classroom.

　　Hu Cheng: (5) , too?

　　Liu Tong: Yes. (6) .

　　Hu Cheng: Where's he?

　　Liu Tong: (7) . He finds a watch. (8) .

　　Hu Cheng: (9) . We must learn from(向……学习)him.

　　Liu Tong: You're right. (10) .

　　Hu Cheng: OK!