One of the most important things in the world is friendship. In order to have friends, you have to be a friend. But how can you be a good friend at school?

    Listen — Listen when they are talking. Don't say anything unless they ask you a question. Sometimes it's not necessary for you to have anything to say; they just need someone to talk to about their feelings.

    Help them — If your friend is ever in need of something, be there to help them. You should try to put them first, but make sure you don't do everything they want you to do. Try to take an extra (额外的) pencil or pen with you to classes in case (以防) they forget one. Have a little extra money in your pocket in case they forget something they need.

    Be there for them — Try to make something for your friend to help make them feel better in hard times. Making cards and encouraging them are among the nicest things you can do for a friend. Marilyn Monroe, a famous U.S. actor, once said, “I often make mistakes. Sometimes I am out of control. But if you can't stay with me at my worst, you are sure not to deserve (值得) to be with me at my best.” Always remember this! If you don't want to stay with your friends when they're in hard times, then you don't deserve to be with them when they're having a good time!

    Try to make plans with your friends. Go shopping, go for ice cream, have a party, go to a movie and so on. Take time to know each other even better by doing something you both enjoy. By planning things together, you both can have a good time. And you'll remember these things when you're all old!

    For centuries, in the countries of South and Southeast Asia, the elephant has been an important part of the culture, economy and religion. And nowhere more so than in Thailand. Unlike its African cousin, the Asian elephant is easily domesticated. The rare so­called white elephants have actually lent the power of royalty to its rulers, and until the 1920s the national flag was a white elephant on a red background. To the early Western visitors, the country's romantic name was "Land of the White Elephant"．

    Today, however, the story is very different. Out of work and out of land, the Thai elephant struggles for survival in a nation that no longer needs it. The elephant has found itself more or less deserted by previous owners who have moved on to a different economic world and a society in the western part. And while the elephant's problems began many years ago, now it has a very low national advantage.

    How does the national symbol turn into ignored animals? It is a story of worse environment and the changing lives of the Thais themselves. According to Richard Lair, Thailand's expert on the Asian elephant and author of the report Gone Astray, at the turn of the last century, there may well have been as many as 100,000 national elephants in the country.

    In the north of Thailand alone, it was estimated that more than 20,000 elephants were employed in transport, 1,000 of them alone on the road between the cities of Chiang Mai and Chiang Saen. This was at a time when 90 percent of Thailand was still forest—a habitat that not only supported the animals but also made them necessary to carry goods and people. Nothing ploughs through thick forest better than lots of sure­footed elephants.

    By 1950 the elephant population had dropped, but still to the number of 13,397. However, today there are probably no more than 3,800, with another 1,350 wandering free in the national parks. But now, Thailand's forest covers only 20 percent of the land. This deforestation (采伐森林) is the central point of the elephant's difficult situation, for it has effectively put the animals out of work. This century, as the road network grew, the elephant's role as a beast of burden decreased.

    Have you ever wondered why birds sing? Maybe you thought that they were just happy. After all, you probably sing or whistle when you are happy.

    Some scientists believe that birds do sing some of the time just because they are happy. However, they sing most of the time for a very different reason. Their singing is actually a warning to other birds to stay out of their territory.

    Do you know what a "territory" is? A territory is an area that an animal ,usually the male, claims(声称)as its own .Only he and his family are welcome there. No other families of the same species(物种)are welcome. Your yard and house are your territory where only your family and friends are welcome. If a stranger should enter your territory and threaten you, you might shout. Probably this would be enough to frighten him away.

    If so, you have actually scared the stranger away without having to fight him. A bird does the same thing. But he expects an outsider almost any time ,especially at nesting(筑巢)season. So he is screaming all the time, whether he can see an outsider or not. This screaming is what we call a bird's song, and it is usually enough to keep an outsider away.

    Birds sing loudest in the spring when they are trying to attract a mate and warn others not to enter the territory of theirs.

    You can see that birds have a language of their own. Most of it has to do with attracting mates and setting up territories.

    As scientists in the Netherlands tried to figure out how to build a super flying robot, they learned from one of nature s flyers: the humble fruit fly(果蝇).And by building this robot, they've gained new insights into how the fly carries out one of its dangerous tasks.

    The robot is called the DelFly Nimble Its wingspan(冀展)is about a foot wide. It has four wings that can beat at 17 times per second, which appear very delicate because they're made of the same material as space blankets.

    In the previous designs, they always had a tail, like a traditional airplane tail, said the robots main designer Matej Karasek. He's based at the Micro Air Vehicle Laboratory at Delft University of Technology in the Netherlands, and he and his colleagues published their findings on Thursday in Science

    “In the previous generations", he said, "flapping wings drove the robot forward while the tail helped to guide and stabilize it. But now the DelFly Nimble is completely controlled by the wings. The challenge then was actually combine the control into the wing movement, and that's what we achieved, Karasek said

    In the latest generation. the wings can each move individually or rotate(旋转)around the body of the robot in order to maximize the machine s agility(灵活 ) The robot can remain in one place in the air for about five minutes on a full battery or fly for more than a kilometer"， Karasek said, "And because the scientists are controlling all the movements, they can use the robot to learn more about how fruit flies actually carry out their dangerous tasks, which has caught the attention of biologists.”

    How fit are your teeth? Are you lazy about brushing them? Never fear: An inventor is on the case. An electric toothbrush senses how long and how well you brush and it lets you track your performance on your phone.

    The Kolibree toothbrush was exhibited at the International Consumer Electronics Show in Las Vegas this week. It senses how it is moved and can send the information to an Android phone or iPhone via a Bluetooth wireless connection.

    The toothbrush will be able to teach you to brush right (don't forget the insides of the teeth!) and make sure you're brushing long enough. “It's kind of like having a dentist actually watch your brushing on a day-to-day basis,” says Thomas Serval, the French inventor.

    The toothbrush will also be able to talk to other applications on your phone, so developers could, for example, create a game controlled by your toothbrush. You could score points for beating monsters among your teeth. “We try to make it smart and fun,” Serval says.

    Serval says he was inspired by his experience as a father. He would come home from work and ask his kids if they had brushed their teeth. They said “yes,” but Serval would find their toothbrush heads dry. He decided he needed a brush that really told him how well his children brushed.

    The company says the Kolibree will go on sale this summer, from $99 to $199, and the U.S. is the first target market.

    The world's insects are going down the path of extinction, threatening a "catastrophic collapse of nature's ecosystems", according to the first global scientific review. More than 40％of insect species are declining and third are endangered, the analysis found. The rate of extinction is eight times faster than that of mammals, birds and reptiles.

    "It should be of huge concern to all of us, for insects are at the heart of every food web. They pollinate (授粉) the large majority of plant species, keep the soil healthy, recycle nutrients, control pests, and much more. Love them or 1oathe them, we humans cannot survive without insects, "said Prof Dave Goulson at the University of Sussex in the UK.

    The analysis, published in the journal Biological Conservation, says intensive (集约型) agriculture is the main driver of the declines, particularly the heavy use of pesticides. Urbanisation and climate change are also significant factors.

    "If insect species losses cannot be stopped, this will have catastrophic consequences for both the planet's ecosystems and for the survival of mankind. It is very rapid. In 10 years you will have a quarter less, in 50 years only half left and in 100 years you will have none," said review author Francisco Sánchez-Bayo, at the University of Sydney, Australia.

    One of the biggest impacts of insect loss is on many birds, reptiles, amphibians and fish that eat insects. "If this food source is taken away, all these animals starve to death," he said. Such effects have already been seen in Puerto Rico, where a recent study revealed a 98％fall in ground insects over 35 years.

    Matt Shardlow, at the conservation charity Buglife, said: "It is thoughtful to see this evidence that shows the pitiful state of the world's insect populations. It is increasingly obvious that the planet's ecology is breaking and there is a need for a strong and global effort to prevent and change these terrible trends."