Researchers at Brigham found about one in five teenagers now have some degree of hearing damage. The researchers did not say why hearing loss has risen, but other experts have strong suspicions. One likely culprit, they say, is MP3 players.

    An MP3 player can be dangerous to hearing when its decibel level is turned up too high. High-decibel sounds can damage nerve endings, called hair cells. If a sound is loud enough, the damage can be permanent. A loud sound can shake the membrane (薄膜) on which the hair cells sit- “like an earthquake”. That shake can break or even uproot hair cells. When that happens, the hair cells are finished. Human ears cannot regrow hair cells. Therefore, when listening to an MP3 player, set a volume limit and avoid exposure to loud sounds.

    On the other hand, the loudness of today's music may not be totally under your control. Music companies have been purposely turning up the volume. It's a trend called the fight for loudness.

    Play a CD from the 1990s. Then play a newly released tune. Don't touch the volume control. You'll probably notice that the new CD sounds louder than the old one. Why? Sound engineers who create CDs are using dynamic range compression (压缩), a technology that makes the quiet parts of a song louder and the loud parts quieter. The overall effect of compression is a louder recording.

    Many musicians and sound engineers aren't pleased. They say that compression is driving down the quality of today, s music, making it sound flat and blaring. Gray Hobish, a sound engineer, explains that music should be a combination of loudness and softness. But music companies want to make music louder so it will stand out. That's important in the competition among recording companies.

    What about listeners? Many teenagers listen to music on the go in noisy places and through headphones, all of which reduce sound quality. So young listeners may not notice the poorer quality of modem recordings. “To their ears,” says Hobish, “the music sounds fine. And they are not aware of the hidden threat of the music they are enjoying.”

    No rows of desks in this classroom, and no teacher lecturing at the front. In fact, that's something Barrie teacher Liz Collett rarely does. Instead, she's on the move, talking to students about their work, from the small group sitting on the floor playing games to others nearby figuring out a math problem.

    The children in this class do not take a spelling test all year－in fact, the school avoids all pencil-and-paper tests－nor do they get assigned homework. Instead, their teacher gives them immediate feedback（反馈）on their work throughout the day.

    Welcome to the school of the 21st century, a place where teachers and students cooperate all the time. Such advanced classrooms are trying things, which some might consider as coddling kids－letting students give a voice-recorded essay instead of a written one or even allowing teens to design their own courses.

    Though some people blame（谴责）schools for dumbing things down（降低教育标准）, others will say such changes are actually based on the newest research on how to attract today's youth and increase not only their interests, but also their achievements. Many of today's school are not holding kid's interests. And if they Ye not interested, they're not learning－and isn't that the point?

“Students today say they want their education to be useful and valuable, and don't want it to be simply repeating the facts. That's the kind of learning that be happening for many kids,” says Penny Milton, a researcher. “What we could argue is that to become good learners, they need to become thinkers.”

    Jan Olson, anther researcher, says schools have been operating the same way since the Industrial Revolution. But the digital age is bringing an education revolution. While using technology is a part of it, what's important for students is being able to use information and understand it, not just remembering it.

    Today's learner needs fewer traditional tests and more “effective” feedback, ongoing discussion with a teacher, which studies have found is the number one factor in improving achievement.

    Most Europeans want small cars. Many Americans prefer large cars. As a result, European automakers produce a large number of economical, light weight cars, while American automakers build bigger, heavier cars.

    The price of gas has much to do with this. The petrol is expensive in Europe, so Europeans naturally prefer cars that will go a long way on a small amount of fuel. There are other reasons. Many European cities have very narrow streets. In these cities a small car is more practical and easier to handle than a large one.

    Some Americans like powerful engines in their cars. They enjoy having wider cars that are comfortable for large families and long trips. They are prepared to pay higher costs to get these advantages. Other Americans, however, have learned to like the small and smart cars. Many visitors to Europe during and after World War I discovered that small cars were fun to drive and easy to park in small spaces. They were delighted to learn how far small cars could go on a few gallons of gasoline.

    In the 1950s many Americans began buying European cars. In 1957, for the first time, the United States imported more cars than it exported. The best seller among these imported cars was a cool-looking but small car from Germany. Americans immediately gave it another name “ the bug”.

    Today, American car buyers have a wider choice. There are big cars for people who want large room, comfort, and power. And there are small cars, mostly imported but some American-made, for people who want easy parking and economical operation.

    Young people can have problems with their minds. Some students become worried because they have to study very hard. Others have trouble getting on well with people like their parents and classmates.

    Li Wen, a junior 2student from No.2Middle School, could not understand his teacher and was doing badly in his lessons. He became so worried about it that he started to cut his finger with a knife. Another student16yearold Yang Fang from No.1Middle School, was afraid of exams. She got very worried in one and when she looked at the exam paper, she couldn't think of anything to write.

    A recent report from Jiefang Daily says about 18% of Shanghai teenagers have mental problems. Their troubles include being worried and very unhappy and having problems in learning and getting on with people. Many students who have problems won't go for advice or help. Some think they will look stupid if they go to see a doctor. Others don't want to talk about their secrets Liang Yuezhu, an expert on teenagers from Beijing Anding Hospital has the following advice for teenagers：

    Talk to your parents or teachers often.

    Take part in group activities and play sports.

    Go to see a doctor if you feel unhappy or unwell.

    The United States will introduce a new and comprehensive(综合的) exam for students who seek to study in American and other English-speaking countries, Xinhua News Agency reported from New York.

    The exam, which stands for a great change from the current English level test, was disclosed by Theresa Chang Wei Jen, associate director of the International Service of the US College Board, America's leading educational organization.

    The Advanced Placement International English Language (APIEL) will be offered for the first time throughout the world on May 10, 2002, said Jen.

    However, the APIEL is a strange title to most Chinese students, and it is unlikely to soon gain the similarity of other already existing exams, such as the TOEFL(Test of English as a Foreign Language), the GRE(Graduate Record Examination), or the IELTS(International English Language Testing System).

    "I have never heard of such a test and I would prefer the IELTS if I need another exam," said Xu Jingyan, a graduating student from Beijing University of Aeronautics and Astronautics, who wants to study in England and has already taken the TOEFL.

    Most of Xu's classmates have never heard of the APIEL. "The APIEL is designed for international students who wish to get university studies in English-speaking countries, including the United States, Britain, Canada, and Australia." said Jen.

    The APIEL has been adopted, said Jen, because the TOEFL can no longer accurately reflect the abilities of students of using the English language comprehensively in an academic environment. Xinhua reported that a fairly large number of foreign students who earned high scores in TOEFL exam turned out to be very ordinary educational performers after admission.

    Compared with the TOEFL, the APIEL measures a student's ability to read, write, speak and understand English through testing his or her skills in listening comprehension, speaking with accuracy(精确) and resourcefulness, and writing with clarity(清晰) and fluency, Jen said.

    Roughly the size of a soda can, sitting on a bookshelf, a relatively harmless device(设备) may be turning friends away from your home. The elephant in your living room is your Internet-connected camera, a device people are increasingly using for peace of mind in their homes. But few stop to think about the effect these devices may have on house guests. Should you tell your friends, for instance, that they're being recorded while you all watch the big game together?

    "It's certainly new territory, especially as home security cameras become easier to fix," says Lizzie Post, president of the Emily Post Institute, America's distinguished manners advisors." I think it will be very interesting to see what manners appear in terms of whether you tell people you have a camera or not, and whether guests have a right to ask that it be turned off, if it's not a security issue. "Post wants to make clear that she's not talking about legal rights, but rather personal preference.

When it comes to security cameras, Post says it's a host's responsibility to make sure guests feel comfortable within their home. If the host casually acknowledges that there is a camera in the room by telling a story about it, that may be enough to provide an opening for a guest to say if they are uncomfortable.

    However, if a contractor(合约工)is working in your home, you don't need to tell them that there are cameras watching. Then again, the camera can also work in contractors' favor. "If anything does go wrong while they're in the house, they don't want to be blamed for it," she says. "In fact, the camera could be the thing that proves that they didn't steal the $20, or knock the vase off the table.