Workers aren't allowed to go into a big underground computer center until they step up to a machine that takes a quick picture of the tiny blood vessels (血管) inside their eyes.

    If the machine can't 1 the picture with images in its computer, the worker is stopped by security guards (保安员).

    Each person has his own way of blood vessels in his or her2.And unlike a key, the way can't be3.Old-fashioned keys and locks may soon be things of the past.High-tech security devices (安全装置) are being fixed at military (军事的) bases, computer centers and banks.Companies that 4 the machines say they'll someday be used in people's homes and cars.

    Already, a Japanese company has fixed ways that recognize (识别) people's fingerprints in 360 new homes.The machines open the doors only for the 5of the houses.The new security ways are selling well because thieves and robbers are getting better at breaking into buildings and computers that are 6 by keys and locks.Since nobody can steal or copy a fingerprint, or one's eyes, the new machines are 7.

    Other new machines recognize one's voice.Two American companies use 8 machines to keep an eye on their computers.Inexpensive voice-recognition machines may someday take the place of locks on cars.The doors would open only for the owners.The machines would 9 the owners as little as $270.Although the up-to-date machines are amazing, scientists must still solve a serious problem.How will a boy borrow his dad's car without borrowing his dad's 10?

    When you hear the word "scientist", what do you think of it? Many people think scientists are people in clean white coats, working in labs( 实验室). Some scientists do work in labs. But there are 1 scientists working in woods and jungles(丛林).  These scientists are called " animal behaviour (行为) scientists", and they study animals as they live in nature. Why don't these scientists catch animals and study them in zoos? The 2 is in the word "behaviour". Animal behaviour scientists want to learn 3 animals behave in their wild homes. When animals live in cages or in zoos, they do not act 4 as they do in the wild. They may fight (打架) 5each other, or they may not eat, or they may not raise (抚养) their babies as they usually do. To see real animal behaviour, scientists must go to the places 6the animals live. So animal behavior scientists go into the jungles, the woods or the deserts. There, 7most important tools are their eyes and ears. They watch and listen to the animals very 8. They write down everything that happened in notebooks. Though they live near the animals, the scientists are careful not to frighten them. If the scientists are 9, the animals will pay no attention to them. Then the scientists can see how the animals really live.

    The animal behaviour scientists hope what they've learned about animal behaviour can provide clues(提供线索) 10people learn to live with animals together more happily.

    You either have it, or you don't—a sense of direction, that is. But why is it that some people could find their way across the Sahara without a map, while others can lose themselves in the next street?

    Scientists say we're all born with a sense of direction, 1it is not properly understood how it works. One theory is that people with a good sense of direction have simply worked harder at developing it. Research being carried out at Liverpool University supports this idea and suggests that if we don't use it, we lose it.

    "Children as young as seven have the ability to find their way around." Says Jim Martland, Research Director of the project. "However, if they are not allowed out alone or are taken everywhere by car, they2develop the skills."

    Jim Martland also emphasizes that young people should be taught certain skills to 3their sense of direction. He makes the following suggestions：

    If you are using a4, turn it so it relates to the way you are facing.

    If you leave your-bike in a5place, put it near something like a big stone or a tree. Note landmarks on the route as you go away from your bike. When you return, go back along the same route.

    Simplify the way of finding your direction by using lines such as streets in a town, streams, or walls in the countryside to guide you. Count your steps so that you know6you have gone and note any landmarks such as tower blocks or hills which can help to find out where you are.

    Now you need never get lost again!