In recent history, there have been some amazing inventions which have changed our lives. The plane has made international travel faster and easier. The Internet has brought people closer. And you must know the names of some famous inventors like Henry Ford or Steve Jobs. But there are many everyday objects which you probably don't notice and you don't know who invented them. Take for example Nils Bohlin who invented the modem-day car seat belt (安全带).

    Before 1959, only two-point seat belts were available, and the only people who often wore them were race car drivers. The two-point seat belt couldn't protect passengers from internal injuries (内伤) during serious car accidents.

    In 1958, Bohlin joined Volvo Car Corporation as a safety engineer. Then he came up with the three-point seat belt to keep passengers from flying out of their cars during collisions. The three-point seat belt used one strap (带子) across the chest (胸部) and another across the legs and then the two joined at me same place.

    Amazingly, this was a very simple idea which no one had tried before. The three-point seat belt was introduced on Volvo cars in 1959. For more people's safety, Volvo made the new seat belt design available to other car makers for free. Since then, engineers have worked to improve the three-point seat belt, but the basic design remains Bohlin's.

    At the time of Bohlin's death in September 2002, Volvo announced that the seat belt had saved more than one million lives since it was introduced.

No one knows when the first kite was made. The first record of a kite was more than 2,000 years ago in China. Han Xin, the leader of an army, wanted to bring down a king. He decided to dig a tunnel (隧道)into the king's palace. He flew a kite over the wall of the palace to make sure the length (长度)of its string (线).In this way, he could determine how long the tunnel should be. His men in the tunnel took the kite string with them. When they reached the end of the string, they knew to dig up.

    Kites have been flown in Japan for hundreds of years. In the 1700s, kites were flown in autumn to give thanks for a good harvest. They were also flown to send good wishes to couples who had their first son. Today in Japan, kites are often flown as part of a celebration, such as the beginning of a new year. And kite festivals are held each year in many parts of the country.

    Kites have been used for scientific purposes in the western world. In 1752，Benjamin Franklin tied a key to a kite and flew it in a storm to find out that lightening was a form of electricity. In the 1890s, Lawrence Hargrave invented the box kite to test ideas about flight. From 1898 until 1933, the United States Weather Bureau (气象局) used box kites to collect weather data. The Wright brothers also experimented (试验)with kites. What they learned helped them make the first airplane flight in 1903.

    Recently, many people have begun to try a new way of shopping through the Internet. They are very interested in it. Why is it becoming more and more popular now? There are some reasons. First, more and more people have their own computers and their computers can be joined with the Internet. So it is possible for many of them to do some shopping through the Internet. Second, shopping through the Internet can save some money and a lot of time. Third, they don't need to go to the shop themselves, Because of these good facts, few people refuse it.

However, some people don't like this new way of shopping. They are worried about the safety of shopping online, Customers can only see the pictures of a product on the Internet. And they can't enjoy the pleasure of buying things in a large supermarket or a wonderful shopping centre. These are the reasons why they do not like it.

    But I think more and more people will like this new kind of shopping in the future.

    We all cry for water when we are thirsty. But do you know, in very hot, dry weather, plants also make very low sounds as if they are crying for help?

    You see, in a plant's stem there are several hundred "water pipes" that bring water from soil all the way up to the leaves. When the ground turns dry, it becomes harder and harder for plants to do this.

    In very hot days, plants have to get any water that they can get.

    Scientists Robot Winter has found out that when plants can get no water, their "water pipes" snap(发出声音). When that happens, the whole plant vibrates(颤动) a little.

    Robot knows that healthy, well-watered plants are quiet. He also knows that dry plants are many insects' favorites and they often attack(袭击) them. How do the insects know which are healthy plants and which are not? Robot thinks that the insects may hear the plants "crying" and they may come to kill them.