ax +ay-a=a×（    ）。

选择适当的选项补全对话。

A: Hello, John.

B: Hi, Mary. Nice to meet you.

A: Nice to meet you,too.    1    

B: Yes, you are right.

A:    2   

B: We can't amve late for class. We can't eat in class and  we can't fight.

A: Can you listen to music after class?

B: Yes, we can.

A:  3  

B: No, we can't.

A:    4   

B: Yes, we do. We have to wear them every day at school.

A:    5   

B: We have to clean the classroom.

A. Do you have to wear uniforms at school?

B. What else do you have to do?

C. What are the rules at your school?

D. Can you run in the hallways?

E. I hear you're studying in Yu Ying Middle School.