I was never very neat, while my roommate Kate was extremely organized. Each of her objects had its place, but mine always hid somewhere. She even labeled (贴标签 ) everything. I always looked for everything. Over time, Kate got nearer and I got messier. She would push my dirty clothing over, and I would lay my books on her tidy desk. We both got tired of each other.

    War broke out one evening. Kate came into the room. Soon, I heard her screaming, "Take your shoes away! Why under my bed!" Deafened, I saw my shoes flying at me. I jumped to my feet and started yelling. She yelled back louder.

    The room was filled with anger. We could not have stayed together for a single minute but for a phone call. Kate answered it. From her end of the conversation, I could tell right away her grandma was seriously ill. When she hung up, she quickly crawled (爬) under her covers, sobbing.

    Obviously, that was something she should not go through alone. All of a sudden, a warm feeling of sympathy rose up in my heart. Slowly, I collected the pencils, took back the books, made my bed, cleaned the socks and swept the floor, even on her side. I got so into my work that I even didn't notice Kate had sat up. She was watching, her tears dried and her expression one of disbelief. Then, she reached out her hands to grasp mine. I looked up into her eyes. She smiled at me. "Thanks."

    Kate and I stayed roommates for the rest of the year. We didn't always agree, but we learned the key to living together: giving in cleaning up and holding on.

    Traveling is a very good activity. When you are fed up with your work and are allowed to take a holiday, you can go to the beautiful spots to enjoy the beauty of nature and the special character of other cities. You can breathe fresh air, visit some places of interest, meet different people and make friends with them. Then you will feel fully relaxed and you will have the energy to undertake the new tasks waiting for you.

    But sometimes, traveling is not an enjoyable thing. For example, when the bus or car you take has a bad accident, you may be trapped in it and waste your time. What's more, the weather can be changeable. If you are climbing a mountain, it may rain suddenly. You may be caught in the rain and may catch a cold. The worst thing is that you may have your money stolen and you may have an injury. All these are terrible things that can happen to a tourist.

    Therefore, before going on a trip, you must prepare yourself carefully. Firstly, you must have clear information about the weather. Secondly, you should choose a good companion so that you can help each other. Thirdly, you must be careful everywhere and try to avoid accidents. If you do these, you can enjoy your travels better and reduce unnecessary trouble.

    One day, Mr. Arnold was teaching a lesson, and things were going as normally as ever. He was explaining the story of human being to his pupils. He told them that, in the beginning, men were nomads (游牧); they never stayed in the same place for very long. Instead, they would travel about, here and there, in search of food, wherever it was to be found. And when the food ran out, they would move off somewhere else.

    He taught them about the invention of farming and keeping animals. This was an important discovery, because by learning to cultivate (耕作) the land, and care for animals, mankind would always have food steadily. It also meant that people could remain living in one place, and this made it easier to set about tasks that would take a long while to finish, like building towns, cities, and all that were in them. All the children were listening attracted by this story, until Lucy jumped up:

    “And if that was so important and improved everything so much, why are we nomads all over again, Mr. Arnold?”

    Mr. Arnold didn't know what to say. Lucy was a very clever girl. He knew that she lived with her parents in a house, so she must know that her family were not nomads; so what did she mean?

    “We have all become nomads again,” continued Lucy, “The other day, outside the city, they were cutting the forest down. A while ago a fisherman told me how they fish. It's the same with everyone: when there's no more forest left the foresters go elsewhere, and when the fish run out the fishermen move on. That's what the nomads did, isn't it?

    The teacher nodded, thoughtfully. Really, Lucy was right. Mankind had turned into nomads. Instead of looking after the land in a way that we could be sure it would keep supplying our needs, we kept developing it until the land was bare. And then off we would go to the next place! The class spent the rest of the afternoon talking about what they could do to show how to be more civilized (文明的).

    The next day everyone attended class wearing a green T-shirt, with a message that said “I am not a nomad!”

    And, from then on, they set about showing that indeed they were not. Every time they knew they needed something, they made sure that they would get it using care and control. If they needed wood or paper, they would make sure that they got the recycled kind. They ordered their fish from fish farms, making sure that the fish they received were not too young and too small. They only used animals that were well cared for, and brought up on farms.

    And so, from their little town, those children managed to give up being nomads again, just as prehistoric men had done, so many thousands of years ago.

    We all long for friendship, but how to make a friend? "The best time to make a friend is before you need one." Joy Steven said. The following are some tips for you.

    People equal friends

    Friends usually begin with strangers. Getting in touch with other people is the first step to make a friend. Friends can't be made in empty air. Best friends take time to make.

    Friends understand friends

    Friends understand each other when talking. Many unpleasant personal quarrels can be avoided if you will take the time to understand others' feelings and points of view.

    Friends touch friends

    Touching is a warm form of communication between friends. When you see best friends communicating, you will notice them stand close together, touch each other comfortably and listen to each other. Sometimes a friendly touch is more powerful than words.

    Friends praise friends

    Praise is a powerful tool to make a friend. Honest praise can affect (影响) your friends' lives. So try to praise your friends including your general ones.

    Friends can loyal (忠诚的) and trustworthy

    Trust and loyalty go hand in hand for friends. Friends can share secrets with you, because good friends never break confidence (信心) and are loyal forever.

    According to a team of researchers, an animal's ability to perceive(感知)time is linked to their pace of life.

    "Our results lend support to the importance of time perception in animals where the ability to perceive time in a very short time may be the difference between life and death for fast moving creatures." commented lead author Kevin Healy from Trinity College Dublin.

    The study was done with a variety of animals using phenomenon based on the maximum speed of flashes of light an individual can see before the light source is seen as constant. Dogs, for example, have eyes with a refresh rate higher than humans.

    One example of this phenomenon at work, the authors say, is the housefly and its ability to avoid being hit. The research showed flies "observe motion in a shorter time than our own eyes can achieve, "which allows them to avoid being hit.

    Professor Graeme Ruxton of the University of St Andrews in Scotland, who worked jointly on the research project, said in a statement, "Having eyes that send updates to the brain at much higher frequencies than our eyes do is of no value if the brain cannot process that information equally quickly. Thus, this work highlights the impressive abilities of even the smallest animal brains. Flies might not be deep thinkers, but they can make good decisions very quickly."

    In comparison, the tiger beetle(虎甲虫)runs faster than its eyes can keep up, basically becoming blind, which requires it to stop periodically to re-evaluate its prey's(猎物)position.

    Our results suggest that time perception offers an as yet unstudied dimension along which animals can specialize and there is considerable range to study this system in more detail.

     At one time, computers were expected largely to remove the need for paper copies of documents because they could be stored electronically. But for all the texts that are written, stored and sent electronically, a lot of them are still ending up on paper.

     It is difficult to measure the quantity of paper used as a result of the use of Internet-connected computers, although just about anyone who works in an office can tell you that when email is introduced, the printers start working overtime. "I feel in my bones this revolution is causing more trees to be cut down," says Ted Smith of the Earth Village Organization.  

     Perhaps the best sign of how computer and Internet use pushes up demand for paper comes from the high-tech industry itself, which sees printing as one of its most promising new markets. Several Internet companies have been set up to help small businesses print quality documents from a computer. Earlier this week Hewlett-Packard Co. announced a plan to develop new technologies that will enable people to print even more so they can get a hard copy of a business document, a medical record or just an online email, even if they are nowhere near a computer. As the company sees it, the more use of the Internet the greater demand for printers.

     Does all this mean environmental concerns have been forgotten? Some activists suggest people have been led to believe that a lot of dangers to the environment have gone away. "I guess people believe that the problem is taken care of, because of recycling," said Kelly Quirke, director of the Rainforest Action Network in San Francisco. Yet Quirke is hopeful that high-tech may also prove helpful. He says printers that print on both sides are growing in popularity.

     The action group has also found acceptable paper made from materials other than wood, such as agricultural waste.