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.

    As space science develops, man has learned more and more about space. Space is not only amazing but also dangerous. While working in space, spacemen are facing danger.

    Scientists have found out that radiation(辐射) is the greatest danger to spacemen in space. When spacemen are working in space, they are in danger of radiation from the sun and other stars, which is bad for their health. Some special medicine may work a little, but there's no really helpful medicine.

    Space junk is also thought a great danger to spacemen. It's reported that there are 9,000 man-made things flying in space. About 30% of these are man-made satellites(卫星),10% are spaceships, and the rest are space junk. An explosion(爆炸) in 1996 made a cloud of 300,000 fragments(碎片), each at least 4 mm in size, and even a small piece of these knocked against a spaceship window and did some damage. Scientists are working on helpful ways to do with space junk.

    Although space is really dangerous, it interests everyone on the earth. In the near future, it may become usual for people to spend a few days in a space hotel. We may even choose to leave the earth and live in space for a few years. So we should care for space and do something to help improve the space environment.

    A small robot may help children who are ill in hospital or at home. These children may feel lonely without their friends or classmates. The robot takes their places at school. Through the robot, the children can hear their teachers and friends.

    The robot is called AV1. A Norwegian company called No Isolation created the robot. Dolva explains how the robot AV1 works. She says from home, children use a tablet or phone to start the robot. Then they use the same device to control the robot's movements. At school, the robot becomes their eyes, ears and voice.

     "So, it sits at the child's desk in the classroom and the child uses a tablet or a phone to start it and control its movements and talks through it. So it's the eyes, the ears and the voice at school." The robot is equipped with speakers, microphones and cameras that make communication easy.

    AV1 is large and looks like a human for a reason. Dolva says this is important because the robot is supposed to be a friend of the children. "It can't be just a tiny camera because the other kids can't pick it up and take it with them. This is supposed to be their friend." And robots are, quite simply, cool. Hopefully AV1 will help some children feel less lonely while they are not in class.

    When you carry your heavy schoolbag on the way to school or home, do you know the fact that the heavy schoolbag influences your interest in learning knowledge? Don't worry. You may be able to say goodbye to your heavy schoolbag in the near future.

    Instead of burying(埋葬) your face in an ocean of textbooks, newspapers, magazines and novels, you will soon find that an E-book reader can take the place of them all.

    An E-book reader is a new kind of mini machine designed to hold thousands of text files and display them on the screen as real text printed(印刷) on a paper page.

    In the same way in which the iPod(a kind of MP3) has changed the way people enjoy music, E-book readers could change the way that books are read. Some scientists have predicted that E-books will be used widely in our daily life, especially in schools.

    The size of an E-book reader is the same as that of real books. Its screen is different from that of a computer. It is as thin as a piece of paper. The words on an E-book reader's screen look exactly the same as those on real pages. However, you can do more with an E-book reader than you can with a real book. The reader can change the size of the words and connect to the Internet to download new books.