In 1901, H. G. Wells, an English writer, wrote a book describing a trip to the moon. When the explorers (探险者) landed on the moon, they discovered that the moon was full of underground cities. They expressed their surprise to the "moon people" they met. In mm, the "moon people" expressed their surprise. "Why are you travelling to outer space when you don't even use your inner space?" they asked.

    H. G. Wells could only imagine the travel to the moon. In 1969, human beings really did land on the moon. People today know that there are no underground cities on the moon. However, the question that the "moon people" asked is still an interesting one. A growing number of scientists are seriously thinking about it.

    Underground systems (体系) are already in place. Many cities have underground car parks. In some cities, such as Tokyo, Seoul and Montreal, there are large underground shopping areas. The "Chunnel", a tunnel connecting England and France, is now completed.

    But what about underground cities? Japan's Taisei Corporation is designing a network of underground systems, called "Alice Cities". The designers imagine using surface space for public parks and using underground space for flats, offices, shopping and so on. A solar dome (太阳能穹顶) would cover the whole city.Supporters of underground development say that building down rather than building up is a good way to use the earth's space. The surface, they say, can be used for farms, parks, gardens, and wilderness. H. G. Wells's "moon people" would agree. Would you?

    In most parts of the world, many students help their schools make less pollution. They join environment clubs. In an environment club, people work together to make our environment clean.

    Here are some things students often do.

    No-garbage lunches. How many lunch bags do you throw away after lunch? Environment clubs ask students to bring their lunches in bags that can be used again. Every week they will choose the classes that make the least garbage and report them to the whole school.

    No-car day. On a no-car day, nobody comes to school in a car including the students and the teachers. Cars give pollution to us, so remember：

    Walk, jump, bike, or run!

    Use your legs! It's lots of fun!

    Turn off the water! Do you know that some toilets can waste twenty to forty cubic meters of water an hour? In a year, that would fill in a small river. In the environment clubs, students mend those broken toilets.

    We love our environment. Let's work together to make it better.

    Many animals are in danger of dying out. We can see the number of animal species decreases faster and faster and this trend will continue. From 1980 to 2010, at least I million animal species disappeared. Worse still, more and more wild animals are in great danger. It is not a piece of terrible news; it is a fact, a harsh reality. Unfortunately, we may not see these animals in the near future.

    Why is the number of animal species declining year by year? Apparently animals have become victims of fashion industry. Animal skin has been used to make fashionable clothes and these clothes are sold at a high price. So some greedy people begin to kill animals in a large quantity.  This irresponsible behaviour not only breaks the balance of nature but also endangers the living environment of human beings.

    As far as I am concerned, something must be done to stop this illegal action. We believe "no buying, no killing". First, we must make concerning laws to protect these animals in danger.  Second, we must take some measures to protect animals effectively. Animals are our friends and part of our environment. Third, we should raise people's awareness to protect animals and our environment.  In this way, we can build a harmonious society and ensure a sustainable development.

    Different weather makes people feel different. It influences health, intelligence（智力）and feelings.

    In August, it is very hot and wet in the southern part of the United States. People there have heart trouble and other kinds of health problems during this month. In the Northeast and the Middle West, it is very hot at some times and very cold at other times. People in these states（州）have more heart trouble after the weather changes in February or March.

    The weather can also influence intelligence. For example, in a 1983 report by scientists, IQ（智商） of a group of students was very high when a very strong wind came, but after the strong wind, their IQ was 10%lower.The wind can help people have more intelligence. Very hot weather, on the other hand, can make it lower. Students in many schools of the United States often get worse on exams in the hot months of the year（July and August）.

    Weather also has a strong influence on people's feelings. Winter may be a bad time for thin people. They usually feel cold during these months. They might feel unhappy during cold weather. But fat people may have a hard time in hot summer. At about 18℃, people become stronger.

    Low air pressure（气压） may make people forgetful（健忘）. People leave more bags on buses and in shops on low-pressure days. People feel best at a temperature of about 18℃.

Are you feeling sad, tired, forgetful, or unhappy today? It may be the weather's problem.

    The coffee shop Starbucks will give people a discount if they bring their own cups. It wants to cut down on the number of paper cups that are put in the rubbish bins. It is part of a two-month experiment in cafes in England. Starbucks wants to reduce waste and recycle more, The president of Starbucks in the UK said, "We are very happy to increase recycling rates(比率)，and reusable cups are a key part of our waste reduction plan." Bosses will decide later if they will continue the discounts. People who bring their own cups will not get a discount on the cafe's cheaper filter coffee.

    The problem of paper cups has been in the news a lot. Around seven million cups are thrown away every day. Reporters say that some cafes lie about how many paper cups they recycle. The reporters say the cafes do not recycle as many cups as they say. Customers wrongly believe that a coffee shop is environmentally friendly. Less than one in 400 paper cups at coffee shops are recycled. A coffee drinker said she would bring her own cup. She said, "I am so sad that cafes recycle so little. I thought they were more responsible."