简答题:根据下面资料，回答51-55题
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
第（51）题答案