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    Research proves that nearly half of the cancers diagnosed(诊断) in the UK each year-over 130, 000 in total- are caused by life choices that include smoking, drinking and eating the wrong things.

    Tobacco(烟草) is the biggest factor, causing 23% for cases in men and 15.6% in women, says the Cancer Research UK report. Next comes a lack of fresh fruit and vegetables in men's diets, while for women it is being overweight. Lead author of the report, Professor Max Parkin, said: "Many people believe cancer is related to fate or in the genes(基因), and that it depends on luck whether they get it or not. Looking at all the evidence, it is clear that around 40% of all cancers are caused by things we mostly have the power to change."

    For men, the best advice appears to be: stop smoking, eat more fruit and vegetables and cut down on how much alcohol you drink. For women, again, the best advice is to stop smoking, but also watch your weight.

    In total, 14 lifestyle and environmental factors, such as where you live and the job you do, cause 134, 000 cancers in the UK each year.

    Some risk（风险） factors are well founded, such as smoking's link with lung cancer. But others are less well recognized. For stomach cancer, a fifth of the risk comes from having too much salt in the diet, data suggests. Some cancers, like mouth and throat cancer, are caused almost entirely by lifestyle choices. But others, like gall bladder cancer(胆囊癌), are largely unrelated to lifestyle.

    Public Health Minister, Anne Milton, said: "By making small changes you can cut your risk of serious health problems- giving up smoking, watching you drink, getting more exercise and keeping an eye on your weight."

    Noise pollution is doing much harm to our health now. Noise, in fact, is unwanted sound and is a kind of invisible (无形的) killer. More and more students enjoy listening to music very much. When they listen to MP3 players, they like to turn up the volume (音量). Some people love listening to loud music. Furthermore, while watching TV, they keep the volume up. But they haven't realized that the noise is weakening their hearing. In fact, the noise not only influences each member in the family, but also makes a difference to the comfort of neighbors.

Noise pollution is a source of increasing misery (痛苦) to people in our society. If people are often disturbed by it, they may feel uncomfortable or upset. What's worse, the noise can make people mad sometimes. If a worker works in a printing factory for too long, his/her hearing loss is much faster than a common person working in a quieter environment. So everybody must pay more attention to noise pollution. Generally speaking, the following four types of noise should be watched out for:

    ◆Noise in the street

    ◆Construction site (建筑工地) noise

    ◆Noise at work

    ◆Transportation noise

    I think the local department (部门) should take measures to control the noise levels, but it's everybody's duty to keep a quiet environment.

    What will man be like in the future — in 5,000 or even 50,000 years from now? We can only make a guess, of course, but we can be sure that he will be different from what he is today. For man is slowly changing all the time.

Let us take an example. Man, even five hundred years ago, was shorter than he is today. Now, on the average, men are about three inches taller. Five hundred years is a relatively (相对地) short period of time, so we may suppose that man will continue to grow taller.

    Again, in the modern world we use our brains a great deal. Even so, we still make use of only about 20% of the brain's capacity (容量.) As time goes on, however, we shall have to use our brains more and more and finally we shall need larger ones! This is likely to bring about a physical change too. The head, especially the forehead, will grow larger.

    Nowadays our eyes are being used too much. In fact, we use them so much that very often they become weaker and we have to wear glasses. But over a very long period of time it is likely that man's eyes will grow stronger.                      

    On the other hand, we tend (有…的趋势) to make less use of our arms and legs. These, as a result, are likely to grow weaker. At the same time, however, our fingers will grow more sensitive (敏感的) because they are used a great deal in modern life.

    What about hair? This will probably disappear from the body altogether in course of time because it does not serve a useful purpose any longer. In the future, then, both men and women are probably to be hairless!

    Perhaps, all this gives the impression that future man will not be a very attractive (有吸引力的) person to look at! This may well be true. All the same, besides these changes, future man will still have a lot in common with us. He will still be a human being, with thoughts and feelings similar to our own.

    In earliest times, men considered lightning to be one of the great mysteries (神秘的事物) of nature. Some ancient peoples believed that lightning and thunder were the weapons (武器) of the gods.

    In reality, lightning is a flow of electricity formed high above the earth. A single flash of lightning 1.6 kilometres long has enough electricity to light one million light bulbs (灯泡).

    The American scientist and statesman, Benjamin Franklin, was the first to show the connection between electricity and lightning in 1752. In the same year he also built the first lightning rod (避雷针). This device (装置物) protects buildings from being damaged by lightning.

    Modern science has discovered that one stroke (闪击) of lightning has a voltage (电压) of more than 15 million volts (伏特). A flash of lightning between a cloud and the earth may be as long as 13 kilometers, and travel at a speed of 30 million meters per second.

    Scientists judge that there are about 2,000 million flashes of lightning per year. Lightning hits the Empire State Building in New York City 30 to 48 times a year. In the United States alone it kills an average (平均数) of one person every day.

    The safest place to be in case of an electrical storm is in a closed car. Outside, one should go to low ground and not get under trees. Also, one should stay out of water and away from metal fences. Inside a house, people should avoid open doorways and windows and not touch wires or metal things.

    With lightning, it is better to be safe than sorry?