B

    You probably know many of the things that you can do with the hundreds of different muscles（肌肉） in your body. But have you ever thought about how the muscles in an animal's body are different from yours? An animal's muscles are made to do the things that are the most important for its life.

    Lions are hunters. They depend on their ability to catch other animals. Lions must be fast in order to catch their prey(猎物). The powerful muscles in their back legs allow them to run at speeds of more than 30 miles per hour. They can also jump a distance of more than 35 feet. The strong muscles in their front legs help them catch their prey.

    Snakes also use their muscles for hunting prey and for movement, but their muscles work in very different ways than lion's do. Because snakes do not have any legs, they use their muscles to push against the ground or other objects to move themselves forward. Their muscles also allow them to eat things that seem much too large. For example, a snake may eat an egg that is larger than the width of its body. How does this happen? The snake's strong neck muscles work together to push the egg down the mouth.

    The elephant's long nose has a lot of muscles. Scientist believe that the nose alone has more than 100, 000 muscles! This is because the elephant uses its nose much in the same way that people use their hands and fingers. Even though the nose is large, it can perform surprisingly tasks. For example, an elephant can pick up a tree by its roots or even to lift a baby elephant.

    The great muscles of these animals seem pretty unbelievable. But the muscles in your body work exactly the way you need them to. After all, it might be fun to be able to jump a distance of 30 feet, but as a human being, there is just not much need for it.

C

    In the future, your automobile will run on water instead of gas! You will be able to buy a supercomputer that fits in your pocket! You might even drive a flying car!

    For each prediction(预言) that has come true today, several others have missed by a mile. Many of these predictions didn't consider how people want to use the technology, or if people really needed it in their lives or not. Let's look at some predictions from the not-too-distant past.

    Robot helpers

    Where's the robot in my kitchen? Nowhere, of course. And he's probably not coming any time soon. Robots do exist today, but mostly in factories and other manufacturing environments.

    Back in the 1950s, however, people said that by now personal robots would be in most people's homes.

    So why it hasn't happened? Probably because robots are still too expensive and clumsy. And maybe the idea of robots cooking our dinners and washing our clothes is just too weird. At home we seem to be doing fine without them.

    Telephones of tomorrow

    In 1964, an American company introduced the video telephone. They said by the year 2000 most people would have a video phone in their homes. But of course the idea hasn't caught on yet.

    Why? The technology worked fine, but it overlooked something obvious: People desire for privacy. Would you want to have a video phone conversation with someone after you just stepped out of the shower?

    Probably not—it could be embarrassing! Just because a technology available(可利用的) doesn't always mean people will want to use it.

    Flying cars

    And finally, how about that crazy prediction of the flying car? It's not so crazy any more! But a flying car remains one of the most fascinating technology ideas to capture our imagination. Keep watching the news or perhaps the sky outside your window to see what the future will bring.

    A study of sleep in sparrows suggests the relationship between sleep and the ability to learn may be more complicated (复杂) than realized．

    Niels C. Rattenborg of the University of Wisconsin—Madison wanted to find out how the sparrows were able to deal with getting so much less sleep．He and his team brought eight wild birds into a lab and watched them for one year．They invented a game to check how well the birds could learn．In the game, the sparrows had to peck (啄) three buttons (按钮) in a certain order to get a food treat．The scientists discovered that the birds' ability to learn the right button order depended on (依靠) two things, the time of year and the

amount of sleep the birds had．

    During the migration (迁徙) season, the sparrows were restless at night and got much less sleep than usual．Even so, they were able to understand how to get the food quickly as if they'd had a regular night of sleep．Outside the migration season, they found the sparrows that got less sleep than usual had much more difficulty learning how to get the food treats than birds that had a regular sleep．

    The results show that the sparrows can deal with much less sleep during the migration season than usual．If scientists can find out why, they may learn from sparrows and find ways of helping people deal with getting much less sleep．Until scientists fully understand the relationship between sleep and learning, it's better to get plenty of sleep when preparing for an exam．

    Now too much CO makes the Earth warmer and warmer, and brings bad effect to people. To save our Earth, a new lifestyle called low-carbon life becomes popular. Low carbon means low energy and no waste. It is necessary for everybody to learn to live a low-carbon life.

    To live a low-carbon life, we'd better save as much energy as we can. For example, turn off the lights and TV when you don't use them, use cold water to wash clothes or dishes: take a short shower and try to take a cold one when the weather gets warm: don't do the cooking with electricity.

    To live a low-carbon life, we should eat less meat. Being a vegetarian can help reduce (v)one and a half ton of carbon dioxide a year, but keeping animals for food produces even more carbon dioxide than all the cars do in the world.

    To live a low-carbon life, we should plant more trees. Trees are very important for us. They can not only produce oxygen for us to breathe and keep the air clean. But also take in the harmful gases from the air. To protect trees we should stop people from cuing down trees and plant as many trees as we can.

    If we can keep them a habit in our daily life, the earth will become a safer planet for us to live on.

    It is a cold and dry winter morning. When you wake up, you feel that your throat hurts. You begin to sneeze and later you may cough. You must have a cold！Wait a moment. Could it just be a common cold or the flu(流感)that's been going around？

    A cold gives you a runny nose and cough. But it's usually easy to deal with. Some people take medicine while others drink herbal tea or chicken soup. Usually you feel better after a week.

    On the other hand, the flu can be much more dangerous. It usually gives you fever. Sometimes it can cause death. According to an American magazine, the worst flu killed about 50 million people from 1918 to 1919.

    Don't worry. If you get a flu vaccine(疫苗), it can stop you from getting the virus(病毒).Flu vaccines work by giving the body a small number of flu viruses. This causes your body to develop antibodies(抗体). So next time you get the flu, the antibodies will help you.

    The flu virus changes every few years. Therefore, there are so many types of flu, such as HlN1 and H5N1.The antibodies for one type of flu can't help us against all types of flu. That's why we need to get the vaccine every year.

    However, good healthy habits may also help stop you developing a cold or flu. Washing your hands often helps stop you from getting viruses. It is also important to get regular exercise and eat healthy food. All these can help you strengthen(增强)your immune system(免疫系统).

    Our life will be different from nowadays with robots appearing in our homes. So what will the future be like? Here are some students' ideas.