阅读下面的短文，从短文后所给的四个选项中，选出可以填入空白处的最佳选项。
The Water City of Venice
In 1980s, I went to Italy for business. One day, I sat with my friend in a well-known coffee shop in a neighboring town of Venice(威尼斯), Italy, the city of lights and 1.
As we enjoyed our coffee, a young man2 glasses entered and sat at an empty table beside us. He called the waiter and placed his order saying, “Two cups of coffee, one of them there 3 the wall.”
We heard this order with interest and found that he 4 with one cup of coffee but he paid for two.
When he left, the waiter 5 a piece of paper on the wall saying “A Cup of Coffee”.
While we were still there, 6 middle-aged men entered and ordered three cups of coffee, two on the table and one on the wall. They had two cups of coffee but 7 three and left. This time also, the waiter did the same. He put a piece of paper on the wall saying, “A Cup of Coffee”.
It was 8 and perplexing(困惑)for us. We finished our coffee, paid the bill and left.
After a few days, we had a chance 9 this coffee shop again. While we were enjoying our coffee, a man 10 dressed entered. As he seated himself, he 11 the wall and said, “One cup of coffee from the wall.”
The waiter served coffee to this man with the customary(惯常的)respect. The man had his coffee and left 12 paying.
We were amazed to watch all this, as the waiter 13 a piece of paper from the wall and threw it into the rubbish bin.
Now it was no 14 for us-the matter was very clear. The great respect for the needy shown by the inhabitants(居民)of this town 15 our eyes well up in tears.
Many years later, when I went to Venice for business again, I did the same thing as my appreciation to this beautiful world.
