完形填空。阅读下列短文，从短文后各题所给的四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项。

    Last Sunday, I sat with Tony, my college classmate, in a well-known coffee shop in Buenos Aires, Argentina. As we1our coffee, two men entered and sat on an empty table beside us.

    They2the waiter and ordered three cups of 3, two on the table and one on the wall. We heard this order with great4and observed that they were served with two cups of coffee 5they paid for three. As soon as they6, the waiter pasted (粘贴) a piece of paper on the wall saying A Cup of Coffee.

    It 7that the matter was normal at this place. However, it was something8for Tony and me. Since we had nothing to do with the matter, we 9our coffee, paid the bill and left.

    After a few days, we again had a10to go to this coffee shop. While we were enjoying our coffee, a man entered. The way this man was dressed did not  11the standard nor the atmosphere of this coffee shop. Poverty was12from the looks on his face. As he13himself, he looked at the14and said, “One cup of coffee from the wall.” The waiter served coffee to this man with15, politeness and warmth.

    After a few minutes, the man finished his coffee and left16paying. We were amazed to watch all this when the waiter 17a piece of paper from the wall and18it in the dustbin.

    Now it was no 19for us because the matter was very clear. Although the man didn't know about the one who was giving this cup of coffee to him, he would have a better understanding of the wall which had a great role between the 20and receiver.

    Robot are about to enter our lives. From doing housework, entertaining and educating our children, to looking after the elderly, scientists say we will soon be welcoming robots into our homes and workplaces.

    Researchers believe we are on the cusp (过渡点) of a robot revolution that will mirror the quick growth of the computer revolution. They are developing new laws for robot behavior, and designing new ways for humans and robots to communicate.

    “I think robots will change who we are, just as eyeglasses and fire changed who we were before, says Rodney Brooks, a director of the MIT Computer Science and Artificial Intelligence Laboratory.

    Some ideas and technologies may sound like science fiction, but they are fast becoming science fact. Robots scientists invented are already beginning to perform everyday tasks like cleaning our floors. The latest types from Japan are able to help the elderly to get out of bed or get up after a fall. They can also remind them when to take medication (药物), or even help wash their hair.

    “Robot now are not human-like. For example they are things like automatic (自动的) beds and wheelchairs,” says Prof Hiroshi Ishiguro at Osaka University, Japan. He believes the time is coming when robots start looking less like machines, and more like us. “In the near future we are going to use more human-like robots. I really think so, says Prof Ishiguro.

    Prof Maja Mataric at the University of Southern California agrees. “I'm very excited about the fact that today we are trying to make robots that look like human beings,” she says.

    “I believe we love robots because they're reflections (反映) of ourselves,” says Ken Goldberg, director of the Berkeley Center for New Media at the University of California at Berkeley.

    “Robots could be used in education, learning, and healthcare, where social support is important,” says Dr. Cynthia Breazeal, director of the Personal Robots Group at MIT.