If you want a more interesting experience when you arrive in a new city or country, here are some better ways to travel, both for you and for the environment.

    Way 1 Get out of the car and walk. It's slower but it's the greenest way to travel. It's also the most rewarding（有益的）way to see a city, but remember to wear comfortable shoes.

    Way 2 Cycling is also  a good choice. Many hotels now  offer free bikes to guests. It is convenient for people to travel around the city. Some also provide electric bikes that make it easier to go up hills and on longer journeys. Some cities also have mobikes, and you can pick up one easily. It's not free but very cheap.

    Way 3 If you have to take transport in a city, try to take public transport. Most cities now offer lots of information and very clear maps at the city's website.

    Way 4 If possible, take buses, trains or ships to travel from city to city. They are usually greener than cars and planes.

    Way 5 When the only way to travel is by car, rent(租) an electric car. Many car rental companies now offer them, so always ask!

    If you do not use your arms or your legs for some time, they will become weak; when you start using them again, they slowly become strong again. Everybody knows that. Yet many people do not seem to know that memory (记忆) works in the same way. When someone says that he has a good memory, he really means that he keeps his memory in practice by using it. When someone else says that his memory is poor, he really means that he does not give it enough chance (机会) to become strong.

    If a friend says that his arms and legs are weak, we know that it is his own fault (过错). But if he tells to us that he has a poor memory, many of us think that his parents may be to blame (责备), and few of us know that it is just his own fault. Have you ever found that some people can't read or write but usually they have better memories? This is because they cannot read or write, they have to remember the things. Since they cannot write them down in a small notebook, they have to remember days, names, songs and stories. Therefore, their memory is being exercised the whole time.

    So if you want to have a good memory, learn from the people：practise remembering things as other people do.

    Are you a big fan of E. T. (Extraterrestrial) or aliens? Then you should read Extraterrestrial Civilizations (《地球以外的文明世界》) by American writer Isaac Asimov (1920~1992). In his 1979 book, Asimov looked at whether there is life beyond the Earth. He also talked about how we might be able to communicate with aliens someday. Asimov even told us that there are possibly about 500, 000 civilizations (文明) in the galaxy(银河系). The book may be a little out of fashion since it came out in the 1970s. But you'll still enjoy the good reasoning (推理 ) and imagination of it. Asimov was a science fiction(科幻故事) master. His most famous works talk about the relationship between robots and humankind.