根据上下文补全对话，在横线上写出所缺少的内容。 A: Excuse me. Is there a post office near here? B: I'm sorry, I don't know. You can ask this policeman, I think. A: 1. ____________________________. Excuse me, sir. I need your help. C: Are you looking for the nearest post office? A: Yes. C: 2.__________________________________________________, turn left at the second crossing, and walk on to the end. The post office is on the right. A: 3.________________________________________________________? C: It's about two kilometers away. You can also take a bus. A: 4.________________________________________________________? C: No. 5 bus. The bus stop is over there, on the other side of the street. A: Thank you very much. C: 5.________________________________________________________