A:Excuse me,where's the post office?B：Sorry,I'm new.YOU can ask the policeofficeman.A：Excuse me,Sir.How can I get to the post office?B：You can take a bus.A:which bus should I take?C：No 18.A：But Where's the bus stop?B：It's over there next to the McDonald.A：Thank you,Sir.B：It's my pleasure.