As a result, songs sound like noise to an amusic. Many amuics compare the sound of music to pieces of metal hitting each other. Life can be hard for amusics. In fact, most people cannot understand what it feel like be amusic. Just going to a restaurant or a shopping center can be uncomfortable or even painful. That is why many amusics have to stay away from places where there is music. However, this can result in social loneliness. "I used to hate parties,"says Margaret, a seventy-year-old woman who only recently discovered that she was amusic. By studying people like Margaret, scientists are finally learning how to identify(辨别) this unusual condition.

  Scientists say that the brains of amusics are different for those of people who can enjoy music. The difference is complex(复杂的), and it is not connected with poor hearing. Amusics can understand other non-musical sounds well. They also have no problems understanding common speech. Scientists compare amusics to people who just can't see certain colors.

Many amusics are happy when their condition is finally diagnosed(诊断). For years, Margaret felt embarrassed about her problem music. Now she knows that she is not alone. That makes it easier for her to explain. "When people invite me to a concert, I just say "No, thanks. I'm amusic." says Margret.

    Noise pollution is doing much harm to our health now. Noise, in fact, is unwanted sound and is a kind of invisible (无形的) killer. More and more students enjoy listening to music very much. When they listen to MP3 players, they like to turn up the volume (音量). Some people love listening to loud music. Furthermore, while watching TV, they keep the volume up. But they haven't realized that the noise is weakening their hearing. In fact, the noise not only influences each member in the family, but also makes a difference to the comfort of neighbors.

Noise pollution is a source of increasing misery (痛苦) to people in our society. If people are often disturbed by it, they may feel uncomfortable or upset. What's worse, the noise can make people mad sometimes. If a worker works in a printing factory for too long, his/her hearing loss is much faster than a common person working in a quieter environment. So everybody must pay more attention to noise pollution. Generally speaking, the following four types of noise should be watched out for:

    ◆Noise in the street

    ◆Construction site (建筑工地) noise

    ◆Noise at work

    ◆Transportation noise

    I think the local department (部门) should take measures to control the noise levels, but it's everybody's duty to keep a quiet environment.

    It is park at the bottom of the ocean. It's cold down there too. There's no air to breathe. The water pressure is high. There may be fishes that could hurt you. The deep sea can be an unpleasant place. But people are still fascinated by it, not just because of the amazing scenery. The seafloor might hold the secret to the beginning of life on Earth.

    Oceans cover more than two-thirds of our planet. Yet, we have explored just a small part of the underwater world. A new project is there to explore the ocean deeper. A new US machine can carry people down to as deep as 6,500 metres. It will take the place of an older machine called Alvin. The old one has been in use for 40 years, but it can only go down to 4,500 metres. Alvin played a key role in many important tasks. Alvin helped biologists collect worms, chemists gather rocks, and oceanographers (海洋学家) map the seafloor and take water sample (样本).

    But now it's about time for a new one. The new machine will be like Alvin. It'll also be about 27 feet long, about the size of a small school bus. The seating area inside will be small, about two metres wide. Like Alvin, it'll carry a pilot and two passengers. It will be able to move like Alvin does. It'll give passengers more chances to enjoy the view. Alvin has only three windows. The new one will have five. It will travel more than a mile an hour faster than Alvin. Getting to the bottom faster and moving around more quickly will allow researchers to make the most of their time underwater.

    There have been many great inventions that changed the way we live. The first great invention was one that is still very important today—the wheel. This made it easier to carry heavy things.

    Then in the early 1800's the world started to change. There was little unknown land left in the world. People didn't have to explore(探测) much anymore. They began to work to make life better.

    In the second half of the 19th century, many great inventions were made. Among them were the camera, the light and the radio. These all became a big part of our life today.

    The first part of the 20th century saw more great inventions: the helicopter in1907, movies with sound in 1923, the computer in 1927, and jet planes in 1930. This was also a time when a new material was first made. Nylon(尼龙)came in 1937. It changed the kind of clothes people wear. 

    By this time most people had a very good life, and man has a desire to explore again. The world was known to man but the stars were not. Man began looking for ways to go into space. Russia made the first step. Then the United States took a step. Since then other countries, including China and Japan, have made their steps into space.

    New inventions will someday allow us to do things we have never yet dreamed of.