It is December 25th, 2050. The people in the city are all celebrating Christmas. I'm the mayor of our city. My citizens and I are holding a big party under the sea, though you wouldn't believe it. But please do not feel excited, you should feel sad because we have to live under the sea. Because of the pollution, the earth has been completely destroyed, from top to bottom. The atmosphere has no oxygen and moisture. As a result, the plants are burned by the strong sunlight with a great number of harmful rays. Of course, none of them are still alive. Not only no green, but also the temperature reaches about 121℃ all day even in winter because there is too much CO2 circling the earth.
On the land, there is no life. Luckily, the sea is not destroyed by human. So, we have to move into the sea. At the bottom of the water, people have built many new cities. There is a lot of advanced* equipment in each city. Computers are used to control all the machines, even the people's life. We can also make the seawater into fresh water. There are two machines making oxygen. If they stop working for only one minute, more than 10 million people will die.
The population of our city is over 30 million and, of course, it is quite crowded. We have lots of high buildings and bridges. The roads are wide, too. Our cars are miniature UFOs, don't be surprised, it is true. At the bottom of the sea you can't see anything, because there is no light all day. However, we have advanced lighting equipment so that we can see the "sun"under the sea. Of course, the advanced lighting equipment is very expensive. And if it doesn't work, we can see nothing under the sea. What should we do then?

    As I was leaving to meet Lynne, my roommate told me that I'd better take some money. But I didn't listen to him. I thought that Lynne would pay because she had invited me. I arrived at the restaurant exactly on time. I'd been told that Americans expect you to be on time. Lynne and I sat at a table in the corner of restaurant and a waitress came and took our order.

    The dinner was a great success. I talked a lot about Saudi Arabia and Lynne told me all about herself. After two hours, the waitress finally came and asked if we wanted one check or two. Lynne said two. We went to the cashier and Lynne paid her check. I was embarrassed (尴尬) when the cashier gave me my bill. I had no money to pay for my meal. Then I had an idea. I pretended to look for something in my pockets and said, “Oh! I forgot my wallet! Can I call my roommate, please?” The cashier showed me where the phone was and I quickly called my roommate. In a few minutes, he arrived with some money, but he couldn't hide how he felt. He laughed all the way home. Now, I think it's funny too, but at that time I was terribly embarrassed. I thought that an invitation to have dinner in the United States meant the same thing as that in China. I guess you have to understand that your customs are only your customs. When you visit a foreign country, you have to learn about their customs, too.

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    Everywhere in the world there are different ways of behaving．When we meet someone，everything we say and do expresses our cultural background．So if you want to get on with someone from another culture，it helps to understand something about these differences．

    Even how we stand depends on our culture．English people talk to each other at an average （平均的） distance of 130 cm，while Italians chat at an average distance of 80 cm．So Italians can think that English people are unfriendly because they stand too far away!And English people can think that Italians are too close．

    Touching is also cultural．The French touch much more than Americans．A French couple may touch 100times in half an hour while an American couple may only touch twice!And French teenagers touch each other much more than American teens．

    Dubai (迪拜) is a good place to travel to. There, you can find many tall buildings, taste lots of delicious food and experience some interesting things. Have you ever been to this city? If you go to Dubai during the summer holiday, you may see a special kind of "taxi". It is a drone (无人机). It flies in the sky by itself！ It is said that Dubai plans to use Chinese—made droes as a self —flying air taxi in July.

    The drone taxi is named EHang 184. A Chinese company(公司)made it. The city of Dubai will start using it in July. It will be the world's first passenger drone, according to Yahoo News.

    The drone taxi can fly up to 3, 500 meters high. It can fly at a top speed of 160 kilometers an hour. It can only take one person.

    How do you call an EHang1842 You use its app(应用程序) on your phone. When the drone comes, you choose the place you want to go to on a touch screen. There is no pilot in the drone. But some people on the ground will be watching it. They will make sure your trip is safe. You don't have to worry about it.

    EHang 184's battery(电池) can only keep about 30 minutes, So it cannot take you further than 50 kilometers.

    Would you like to take a trip in this flying drone? Don't wait. Let's go!