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'Swalk.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 .