In a world today of immense technology, population growth and economic flourish, planning for future residential (适合居住的) and commercial developments needs careful analysis with well thought through assumptions about effects on the environment and the people of the community.

    One example of a growing city is Wooster, Ohio, my place of residency, Wooster in the last five years has grown considerably in population, leading to a growth in commercial business. Surrounded by farmland, Wooster's planning commission chose to extend the community into these farm areas in the form of residential and commercial areas.

    Picture this—corn fields, old trees, clean air, country roads, and wildlife are all part of the area. Within four years, the people living on this farm step outside on their front porch to view an extensive shopping center containing Wal-Mart, McDonald's, Wendy's, TCBY, and a Cinemark movie theatre. The once quiet road is now a city street with traffic lights, busy with automobiles day and night. The air smells of car exhaust and fast food.

    Some destruction of farmland is unavoidable when a city expands. Instead of expanding outward, planning commissions should consider interior(内部的) remodeling of a city. Tearing down unusable buildings could remodel many areas inside the city. In addition, commercialized buildings could extend upwards to avoid unnecessary use of land.

    Environmentally, commercial expansion is harmful to the land. Besides forms of pollution, wildlife, including both plants and animals, is put at risk. A planning commission could have realized the benefits of environmental protection. Why not preserve the beauty and naturalness of the land while at the same time allowing for growth?

    With a steady growth of population and the need for more homes and more workplaces, many problems arise when planning for the future. The hillsides, fields and animal habitats need to be preserved while expanding cities. In the future, a world covered with concrete and asphalt（沥青）could become reality. Serious research and analysis are needed when planning for the future of our home communities and for the entire globe to avoid such a miserable result．

    For Suilasaikhan, a man living in the Inner Mongolia Autonomous Region(IMAR)(内蒙古自治区), life was hard years ago. When the wind blew, the sand made it almost impossible for him to see anything. He had to find his way back home by following the barking of dogs.

    Thankfully, things are much better today. About one third of the desert is now covered with trees, and sandstorms are less common. Ian Teh, who comes from Malaysia, came to China last year and was amazed to see people planting trees in the several deserts in northern China. "To be honest, it was hard to imagine it was ever a desert at all," he said.

    These are the results of Chinas years-long efforts to deal with desertification (沙漠化). In the 1950s, this widespread problem affected the life of about 400 million people in 18 provinces and autonomous regions in China. So China started several programs to deal with it. For example, the Three-North Shelter Forest Program, saw thousands of trees planted in northern China.

    In 1994, China joined the United Nations' convention (公约) against desertification and created the world's first law on sand prevention in 2001. With these efforts, the past five years have seen the area of desert in China decrease by 242,400 hectares.

    Desertification isn't the problem only in China. With china's success in dealing with desertification, the United Nations Environment Program (UNEP) believes the country is a good example for other countries to follow. "China is one of the most successful countries in greening the desert and has lessons to share with the world." UNEP Executive Director Erik Solheim told Xinhua.

    E-mail systems at thousands of companies and government offices around the world were attacked by a virus(病毒)called “Melissa” that disguises(伪装)itself as an “important message from a friend. In spite of a weekend of warnings，more than 50 000 computers at about 100 places around the world have been attacked by the virus，computer security experts said on Monday.

    The virus began to show up last Friday and spread rapidly on Monday by making computers fire off dozens of infected(被传染的)e-mails. Although the virus causes no serious damage to a computer，its effect was far reaching.

    To make matters worse，a similar virus called “Papa” was discovered on Monday. Papa is programmed to send out even more infected e-mails than Melissa.

    The Melissa virus comes in the form of an e-mail，usually containing the subject line“Important Message”. It appears to be from a friend. The body of the e-mail message says，“Here is that document you asked for...,don't show it to anyone else.” Attached(附)to the message is a document file.

    Once the user opens that file，the virus digs into the user's address book and sends infected documents to the first 50 addresses. E-mails from the Papa virus include an attached spreadsheet(电子数据文件)file. When the user opens that file，the virus sends 60 infected e-mails.

    The reason why this is spreading so fast is that you are getting it from people you know. You should never open documents or attachments from people you don't know. People who get an unexpected e-mail with the “important message” subject line should delete it immediately and not open the message.

    Animals, including insects, do not have a language like ours. They do not talk to each other in words and sentences. But if we watch them, we can see that they do have ways of communicating with each other.

    Can you see the rabbits' tail? When rabbits see this white tail moving up and down, they run too. The rabbit has reminded them of potential dangers without making a sound. It has given them a signal.

    Many other animals use this kind of language. When a cobra (眼镜蛇) is angry, it raises its hood (兜帽) and makes itself look fierce. This warns other animals. When a bee has found some food, it goes back to its home. It cannot tell the other bees where the food is by speaking to them, but it does a little dance in the air. This tells the bees where the food is.

    Some animals say things by making sound. A dog barks, for example, when a stranger comes near. A cat purrs (猫的呜呜声) when pleased. Some birds make several different sounds, each with its own meaning. Sometimes we human beings speak in the same way. We make sounds like “Oh” or “Ah!” when we are frightened or pleased or when we drop something on our toes.

    But we have something that no animals have — a large number of words which have the meanings of things, actions, feeling or ideas. We are able to give each other all kinds of different information in words and sentences, which no other animals can do. No other animals have so wonderful a language as we have.

    The plan: turn Mars into a blue world with streams and green fields, and then fill it with creatures (生物) from the earth. This idea may sound like something from a science fiction (科幻小说), but it is actually being taken seriously by many researchers.

    This suggested future for the "red planet" will be the main topic for discussion at an international conference hosted by NASA (美国宇航局) this week. Leading researchers as well as science fiction writers will attend the event. It comes as NASA is preparing a multi billion dollar Mars research programme. "Turning Mars into a little earth has long been a topic in science fiction," said Dr Michael Meyer, NASA's senior scientist for astrobiology (太空生物学). "Now, with scientists exploring the reality, we can ask what are the real possibilities of changing Mars."

    Most scientists agree that Mars could be turned into a little earth, although much time and money would be needed to achieve this goal.

    But many experts are shocked by the idea. "We are destroying our own world at an unbelievable speed and now we are talking about ruining another planet," said Paul Murdin, of the Institute of Astronomy, Cambridge, UK. Over the past months, scientists have become increasingly confident they will find Martian life forms. Europe and America's robot explorers have found proof that water, mixed with soil, exists in large amounts on the planet.

    In addition, two different groups of scientists announced on March 28 that they had found signs of methane (甲烷) in the Martian atmosphere (大气). The gas is a waste product of living creatures and could be produced by microbes (微生物) living in the red planet's soil.

    But scientists such as Dr Lisa Pratt, a biologist at Indiana University, say that these microbes will be put in danger by the little earth project. "Before we have even discovered if there is life on Mars, we are talking about carrying out projects that would destroy all these native life forms, all the strange microbes that we hope to find buried in the soil," said Dr Pratt. This view is shared by Monica Grady, a planetary scientist at the Natural History Museum, London. "We cannot risk starting a global experiment that would wipe out the precious information we are looking for." she said, "This is just wrong."

    We tend to think of our dreams as being uniquely personal­nighttime stories built from our own experiences that help us process our day-to-day lives. While dreams can give us a look into our personal selves, scientists have collected data that suggests dreams make their way into our cultural fabric(结构), showing themselves in ways that shape beliefs and expose collective anxieties.

    Roger Ivar Lohmann of Trent University conducted research with the Asabano people of the rainforest of Papua New Guinea, a unique group who didn't have outside contact until 1963. His studies looked at how dreams shape their beliefs and actions.

    According to Lohmann's research, dreams act as a sort of motivator or determinant of Asabano behavior. For instance, a dream may affect the way a person hunts or goes about treating medical conditions. The way dreams determine behavior is due to what Lohmann calls the "night residue" effect. This means that specific memories of dreams can affect the way a person acts when awake and inform their belief system.

    Dreams also seem to have an effect on the way many define themselves within their own cultures, and how sometimes reaching a distinct definition can cause anxiety.

    Matt Newsom of Washington State University spoke with college students in Berlin, and found many students had dreams surrounding conflicting views about their own identities(身份) in relation to what they saw as a return of German nationalism, which is a sensitive subject especially when we think of German identity as it's defined even many years after World War Ⅱ.

    Many students had dreams that centered around anxieties like "Where do I belong?" Many students never talked with one another about identity struggles in their dreams, yet many reported having such dreams. Newsom noted that dreams can be helpful "for identifying (识别) unspoken social and historical anxieties present in a given society."

    All of this research suggests that dreams can do more than help explain the thought of a person; we can learn about entire cultures and collective attitudes as well.