题目内容：
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 .
答案解析：