根据短文理解，完成下列各题。

      Have you noticed your life becoming a little easier? Now, when you go to a certain shopping mall, you can enjoy its free Wi-Fi there. When you want to take a taxi, you can book one with your phone. In fact, all these can be seen as the basic parts of a smart city.

     The idea of a smart city was brought up by US company IBM in 2010. Generally, a smart city is a city that uses digital technologies such as the Internet to improve city planning, save money and resources, and make our life convenient. How smart can a city be? Here are great examples that we can learn from.

      In 2009, Dubuque became the first smart city in the US. The city used smart water meters to take the place of traditional water meters. They can detect（探测〉water waste and leakage（泄漏）and send data to let the house owner know. The same system is used for other city resources like electricity and natural gas. This way, people know how they use their resources and are glad to help reduce waste.

       Santander in Spain also gives us a look at the future. If people point a phone toward a nearby bus stop, the phone immediately shows all bus lines that serve the stop as well as their arrival times. The government organized a research team and provided an App（应用程序〉that collects data on almost everything: light, temperature, and the movements of cars and people. Opening the App near a supermarket provides immediate information on special.

    December 25 is Christmas Day(圣诞节). Christmas is an important holiday in many countries. On Christmas Day, most families get together for a big dinner. They give presents to each other and visit friends. The Christmas tree is an important part of the Christmas holiday. Most families buy trees. The families decorate(装饰) the tree together. Parents usually tell their children that Father Christmas comes during the night and brings presents to good children. Of course, Father Christmas isn't real. The parents of the children are really "Father Christmas". They put the presents under the tree or into their children's stocking(长统袜) after the children go to sleep.

    Some British and American people like to invite friends and colleagues(同事）for a meal at home. You should not be upset if your English friends don't invite you home. It doesn't mean they don't like you.

    Dinner parties usually start between 7 and 8 pm, and end at about 11.Ask your hosts what time you should arrive. It's polite to bring flowers, chocolates or a bottle of wine as a present.

    Do you want to be extra(特别的）polite? Say how much you like the room, or the pictures on the wall. But remember--not to ask how much things cost.

    You'll probably start the meal with soup, or something small as a “starter”(开胃菜),then you'll have meat or fish with vegetables, and then a dessert, followed by coffee. It's polite to finish everything on your plate and to take more if you want it. Some people eat bread with their meal, but not everyone does.

    Before they take out their cigarettes after the meal, most people usually ask, “Do you mind if I smoke here?” Did you enjoy the evening? Call your hosts the next day, or write them a short “thank you” letter. Perhaps it seems funny to you, but British and American people say” thank you ,thank you, and thank you” all the time.