The world's forests become smaller and smaller. People are still cutting down the trees. Why is this happening? There are two reasons—land and wood. People need land for animals and crops. And people want wood. Japan, Europe and North American need wood. There, it is used for buildings or it is made into furniture.

    But most places from the forests are not good for animals or crops. The soil (土壤) in the forests is very thin. When trees are cut down, the soil is washed away by the rain or the wind. Soon there is nothing but sand. Then more land will be needed and more trees will be cut down.

    Teenagers are known for being creative and full of new ideas. Let's have a look at these teenage inventions that might change the world.

    Mobile phones are very popular with people. They are becoming smaller and more convenient.

    Now the scientists in Canada made a smart phone (智能手机)from electronic paper. The Paper Phone is flexible. People can control it by bending it or writing on it with a pen.

    Though the Paper Phone is only millimeters (毫米)thick, people can do many things with it. For example, people can use it to make phone calls, read books, watch movies and play music. So many people use it as a computer.

    The scientists think there will be no paper in the office. And people can store what they want in the Paper Phone.

    The scientists from Queen's University in Kingston, Canada said the Paper Phone would be in style in the future. It may be the end of paper and printers.

    To make people be interested in this kind of mobile phones, the scientists will make it more beautiful. People will see the Paper Phone on May 10 this year.

    Every time when I look at the moon, I wish I could go there. Do you wish you could fly to the moon in a spaceship one day?

For hundreds of years, men have wanted to travel to the moon. When they looked at the moon, they asked many questions. Was the moon hot or cold? Were there any plants or other living things there? There were many, many other questions.

    We know much about the moon now. Scientists have studied the moon for many years and have found out many facts. So far, some men have got to the moon on spaceships.

    Scientists have found that the moon is much smaller than the earth. It is about one quarter the size of the earth. It is traveling round the earth all the time. There are not any plants or other living things on the moon, because there is no air or water there.

    Days and nights on the moon are very long. One day on the moon is as long as two weeks on the earth. One night is also as long as two weeks on the earth. In the day the moon is very hot. At night it is very cold. The moon is much hotter and much colder than the earth.

    There is another surprising thing. On the moon things are not as heavy as they are on the earth. Isn't that interesting? Perhaps one day we can all travel to the moon. It must be great fun.