The electric eel is an amazing storage battery. It can seed a jolt of as much as eight hundred volts of electricity through the water in which it live. ( An electric house current is only one hundred twenty volts.) As many as four-fifths of all the cells in the electric eel's body are specialized for generating electricity, and the strength of the shock it can deliver corresponds roughly to length of its body.
        Yet, people began to understand how electricity works only a little more than two centuries ago. Nature has apparently been experimenting in this field for million of years. Scientists are discovering more and more that the living world may hold many interesting secrets of electricity that could benefit humanity.
     All living cell send out tiny pulses of electricity. As the heart beats, it sends out pulses of record; they form an electrocardiogram, which a doctor can study to determine how well the heart is working. The brain, too, sends out brain waves of electricity, which mbt shoes can be recorded in an electroencephalogram. The electric currents generated by most living cells are extremely small - often so small that sensitive instruments are needed to record them. But in some animals, certain muscle cells have become so specialized as electrical generators that they do not work as muscle cells at all. When large numbers of these cell are linked together, the effects can be astonishing.
     The modern age is an age of electricity. People are so used to electric lights, radio, televisions, and telephones that it is hard to imagine what life would be like without them. When there is a power failure, people grope about in flickering candlelight, cars hesitate in the streets because there are no traffic lights to guide them, and food spoils in silent refrigerators.

    It has been estimated that smokers have made up half of the population in China. And the smokers are becoming  younger and younger, even ineluding some middle school students.Nowadays more and more people have realized smoking can do harm to people＇shealth. However, some people still enjoy smoking. Why? Because some of them think it is a kind of fashion, some think it is of great fun and others, think that smoking can refresh themselves.In fact, smoking is a bad habit. It can cause a lot of diseases. Meanwhile smoking is a waste of money. Besides, careless smokers may cause dangerous fires.Smoking is harmful and it is not only bad for smokers themselves, but also bad for non-smokers.Therefore, I hope all the smokers can give up smoking for themselves and also for the people around them.

    It is said that there are about half of people in China are smoking.Many young boys and girls have the habit of smoking, though they are middle school students like mbt shoes.As we all know, smoking does great harm to human beings. More and more people have come to realize how serious this problem is. But they are never bored with it. Some people think it is a kind of fashion, some think it is of great fun and others think that smoking can refresh themselves.Smoking causes many illnesses. A lot of people always cough because of smoking. The most serious illness caused by smoking is lung cancer. Meanwhile smoking is a waste of money. Besides, careless smokers may cause dangerous fires.
    In order to keep healthy, we should get rid of the bad habit of smoking. Please stop smoking at once.

    Don't you see the heavy smokes from the big chimneys? Don't you smell the gas from the motors all around the streets? We've got much dirtier air! the iceburgs are melting from the warmer winter because of the air pollution!
    Don't you see there are less lives in the water? Don't you see mbt shoes that we must pay higher cost in water processing? We've got much darker water running around! the oceans are in GREat danger.
    Don't you see the montains getting bald? Don't you see our ground becoming hollow? We've been exhausting the resources beneath the earth. Our grandchildren will live on nothing.
    We have only one globe. Treasure the mother nature!