6.What are you going to do？

5.That’s a good idea.

4.Happy Teachers’ Day !

3.It doesn’t matter.

2.Excuse me. I’m sorry I’m late, because the traffic is bad.　

1.Welcome backto school!

11. Good luck(with sb)!

III. 交际用语

10. say goodbye to sb.

9. ask sb. for sth.

8. You’d better do sth.