根据中文提示，把对话中缺少的内容写在线上。这些句子必须符合英语表达习惯。打句号的地方，用陈述句；打问号的地方，用疑问句。

提示：Lucy要去艺术展览中心，向一位男士问路，该男士告诉她如何前往。

(L =Lucy; S =Sir)

L: Excuse me, sir. 　51　 the Art Exhibition Centre?

S: Yes, but it is quite far. It's about an hour's walk. You can take a bus there.

L: 　52　?

S: You can take Bus No. 15.

L: 　53　?

S: About 20 minutes. And you can also take a taxi.

L: Taxi? That's a good idea. Thank you very much.

S: 　54　 .

L: Goodbye.

S:　55　.