一位俄罗斯商人带着笨重的货物从符拉迪沃斯托克海港去莫斯科，既经济又便捷的交通方式为[     ]

A．铁路

B．公路

C．海运

D．航空

根据内容，补全对话。   

A: 1_____ me, is 2_____ a post office near here?

B: 3_____. I don't know. Let's ask Mr. Wang. Mr. Wang, 4___ _ is the post office?

C: Oh, it's very far 5_____ here, but you can 6_____ a taxi.

A: Oh, no,1 want to go there on foot.

C: OK, let me tell you the way. Go down this street and 7_____ left, it's down Bridge

     Street 8____  the right. It's across 9           a big hotel.

A: 10_____. 

C: You are welcome.