《新世纪研究生公共英语教材阅读A》课文.doc

Stephen新世纪研究生公共英语教材阅读A课文Unit 3 Ocean of SandFrom The Guardian1. There is more deserts than sun and sand. On these two pages you can find out how plants, animals and people manage to survive in these apparently barren places. 2. All deserts are dry. The hot, sandy places we think of when we talk about deserts are subtropical deserts. They are found near the Tropics of Cancer and Capricorn where the warm air which rises at the Equator sinks down again, giving a climate of clear skies and very low rainfall. The Sahara is almost one-third the size of Africa, and is nearly as big as the U. S. A. , the fourth largest country. It was not always a desert. Over millions of years it has been convered in ice, sea, forests and grasslands. 3. Desert winds are usually dry. Some deserts are in “rain shadow” areas where the winds have lost what moisture they had crossing high ground. Others are in the middle of continents where the winds blowing over them have lost any moisture gained from distant oceans. The Gobi desert in Mongolia in Asia is an example of such an inland desert. The Atacama in northern Chile is the driest desert on Earth. Parts of the desert had no rain for 400 years, from 1570 to 1971, and in other parts, rains had never been recordedn. One of the sandiest deserts is the Takla Makan. Sandstorms can whip up the sand as high as 3, 048 m(10. 000 ft). Windblown sand in the Sahara can be so fierce that it will sandblast the point off a car or aeroplane. The temperature at night in a hot desert can drop below freezing, to -4(24). During the day, the sand can be as hot as 79(175). Living in a desert climate4. Deserts are difficult places in which to live. During the day they are very hot. In the Libyan Desert in North Africa the temperature on 13 September 1922 reached 58C in the shade! But desert nights are often cold because clear skies allow heat to escape into the atmosphere. The lack of water caused by low rainfall is bad enough, but rainfall is also highly unpredictable. Years of drought can end in tremendous rainstorms. Many desert areas are bare rock, or are covered with pebbles and gravel. Sand accounts for only about 15 per cent of the earths desert regions. In some deserts, the total rain for the year might fall in only two or three storms. But that is enough for plant seeds to sprout and bloom, turning parts of the desert into carpets of flowers for a few days. How plants survive 5. Within a few hours of rain falling, thousands of flowering plants will start to appear. Seeds of plants such as the desert dandelion lie in the ground for years waiting for the rain. 6. These plants die as the desert dries out again, leaving their seeds for the next rains. Other plants have adapted to the harsh environment by storing water in their leaves, stems or roots. The American saguaro cactus can hold 6 to 8 tones of water. Desert plants often have spreading root systems which extract every drop of moisture from the ground. The roots of the mesquite bush can be 20m deep. 7. Plants generally lose water through pores in their leaves. To prevent this, desert plants have small waxy leaves and fewer pores. Many close their pores during the day so they do not lose moisture. To protect themselves against grazing animals, some plants have thorns or an unpleasant taste. Cacti are protected by their sharp spines. Cacti are found only in American deserts. The tallest are saguaros which can reach 15m (50 ft) tall, weigh 7 tons and live for 200 years. Water is stored in the stem and used in times of drought. Animal life 8. Although deserts seem empty, few are without animals. Most animals shelter from the daytime heat in holes or burrows. The burrows trap moisture are stay cooler than the ground above. In the cooler evening or at dawn, the animals emerge. 9. Smaller mammals often have large ears. During the day, the animal loses heat through its ears. In the dark, large warn the animal of unseen dangers. 10. Reptiles venturing out in daytime try to avoid touching the hot sand. The Australian bearded lizard sometimes runs on its hind legs only. The aptly named sidewinder snake only touches the ground in two places. 11. All desert animals survive on little water. Many small animals live on the moisture in their food. Larger animals such as the camel can go without water for days, but drink huge amounts when they get the chance. A camel can drink 10 litres of water in a minute. Desert peoples12. Over thought of years, people have learnt how to survive in Deserts. The San people of the Kalahari desert in southern Africa and the Australian Aborigines hunt animals and gather food plants. They learn traditional skills from older people. 13. On the edges of the desert, nomadic peoples graze flocks of sheep and goats. They are constantly moving to fresher pastures. Nomads such as the Tuareg of the Sahara in North Africa wear loose chothing to protect them sand and heat. Tuareg men protect their faces with a veil. 14. In some deserts, oases (fertile areas) form around wells or springs. Around oases there are settlements and something farms. The mud-brick houses are kept cool by their thick windowless walls. On the move15. Deserts are spreading. Already 12 percent of the worlds land is desert, and every year another 12 million hectares become useless for farming. As the following shows，desertification has many causes. The end result is that the soil becomes exposed and is easily eroded. 16. Throughout the world，governments and aid agencies try to prevent desertification. There are no simple answers, but successful projects have helped people in poorer countries to help themselves. The schemes use knowledge and resources that are readily available to local communities. They include: planting trees and hedges to protect crops from grazing animals and wind erosion. In some areas，people have built lines of stones across slopes to prevent rainwater running away and to allow it to soak into the soil. Unit 4 Three Kinds of FatigueFatigue is one of the most common complaints brought to doctors, friends, and relatives. Youd think in this era of labor-saving devices and convenient transportation that few people would have reason to be so tired. But probably more people complain of fatigue today than in the days when hay was baled by hand and laundry scrubbed on a washboard. The causes of modern-day fatigue are diverse and only rarely related to excessive physical exertion. The relatively few people who do heavy labor all day long almost never complain about being tired, perhaps because they expect to be. Today, physicians report, tiredness is more likely a consequence of under-exertion than of wearing yourself down with over-activity. In fact, increased physical activity is often prescribed as a cure for lowering energy. Physical. This is the well-known result of overworking your muscles to the point where metabolic waste productscarbon dioxide and lactic acid accumulate in our blood and reduce your strength. Your muscles cant continue to work efficiently in a bath of these chemicals. Physical fatigue is usually a pleasant tiredness, such as that which you might experience after playing a hard set of tennis, chopping wood, or climbing a mountain. The cure is simple and fast: You rest, giving your body a chance to get rid of accumulated wastes and restore muscle fuel. Pathological. Here fatigue is a warning sign or consequence of some underlying physical disorder, perhaps the common cold or flu or something more serious like diabetes or cancer. Usually other symptoms besides fatigue are present that suggest the true cause. Even after an illness has passed, youre likely to feel dragged out for a week or more. Take your fatigue as a signal to go slow while your body has a chance to recover fully even if all you had was a cold. Pushing yourself to resume full activity too soon could lead to a relapse (旧病复发) and almost certainly will prolong our period of fatigue. Even though illness is not frequent cause of prolonged fatigue, its very important that it not be overlooked. Therefore, anyone who feels drained of energy for weeks on end should have a thorough physical check-up. But even if nothing shows up as a result of the various medical tests, that doesnt mean theres nothing wrong with you. Psychological. Emotional problems and conflicts, especially depression and anxiety, are by far the most common causes of prolonged fatigue. Fatigue may represent a defence mechanism that prevents you from having to face the true cause of your depression, such as the fact that you hate your job. It is also your bodys safety mechanism for expressing repressed emotional conflicts, such as feeling trapped in an ungrateful role or an unhappy marriage. When such feelings are not expressed openly, they often come out as physical symptoms, with fatigue as one of the most common manifestations. Many people who are extremely fatigued dont even know theyre depressed, Dr. Bulette says. Theyre so busy distracting themselves or just worrying about being tired that they dont recognize their depression. ”There is a great deal you can do on your own to deal with both severe prolonged fatigue and those periodic washed-out feelings. Vitamins and tranquilizers are almost never the right answer, sleeping pills and alcohol are counterproductive, and caffeine is at best a temporary solution that can backfire with abuse and cause life-disrupting symptoms of anxiety. Instead, you might try: DietIf you eat a small breakfast or none at all, youre likely to experience mid-morning fatigue, the result of a drop in blood sugar, which your body and brain depend on for energy. For peak energy in the morning, be sure to eat a proper breakfast, low in sugar and fairly high in protein, which will provide a steady supply of blood sugar throughout the morning. Coffee and a doughnut are almost worse than nothing, providing a brief boost and then letting you down with a thud. ExerciseContrary to what you may think, exercise enhances, rather than saps, energy. Regular conditioning exercises, such as jogging, cycling, or swimming, help you to resist fatigue by increasing your bodys ability to handle more of a work load. You get tired less quickly because your capability is greater. Exercise also has a well-recognized tranquilizing effect, which helps you work in a more relaxed fashion and be less dragged down by the tensions of your day. At the end of a day exercise can relieve accumulated tensions, give you more energy in the evening, and help you sleep more restfully. SleepIf you know youre tired because you havent been getting enough sleep, the solution is simple: Get to bed earlier. Theres no right amount of sleep for everyone, and generally sleep requirements decline with age. Find the amount that suits you best, and aim for it. Insomnia(失眠) and other sleep disorders should not be treated with sleeping pills, alcohol, or tranquilizers, which can actually make the problem worse. Know yourselfTry to schedule your most difficult jobs for the time of day when youre at your peak. Some are morning people who tire by mid-afternoon; others do their best work in the evening. Dont overextend yourself, trying to climb the ladder of success at a record pace or to meet everyones demands or expectations. Decide what you want to do and what you can handle comfortably, and learn to say no to additional requests. Recognize your energy cycles and plan accordingly. Many women have a low point premenstrually, during which time extra sleep may be needed and demanding activities are particularly exhausting. Take breaksNo matter how interesting or demanding you work, youll be able to do it with more vigor if now and again you stop, stretch, and change the scenery. Instead of coffee and a sweet roll on your break, try meditation, yoga, callisthenics , or a brisk walk. Even running up and down the staircase can provide refreshment from a sedentary job. If your job is physically demanding, relax in a quiet place for a while. The do-something-different rule also applies to vacation; getting away from it all for a week or two or longer can be highly revitalizing, helping you to put things in perspective and enabling you to take your job more in stride upon your return. Unit 5 Bringing Up ChildrenIt is generally accepted that the experiences of the child in his first years largely determine his character and later personality. Every experience teaches the child something and the effects are cumulative. “Upbringing” is normally used to refer to the treatment and training of the child within the home. This is closely related to the treatment and training of the child in school, which is usually distinguished by the term “education”. In a society such as ours, both parents and teachers are responsible for the opportunities provided for the development of the child, so that upbringing and education are interdependent. The ideals and practices of child rearing vary from culture to culture. In general, the more rural the community, the more uniform are the customs of child upbringing. In more technologically developed societies, the period childhood and adolescence tends to be extended over a long time, resulting in more opportunity for education and greater variety in character development. Early upbringing in the home is naturally affected both by the cultural pattern of the community and by the parents capabilities and their aims and depends not only on upbringing and education but also on the innate abilities of the child. Wild differences of innate intelligence and temperament exist even in children of the same family. Parents can ascertain what is normal in physical, mental and social development, by referring to some of the many books based on scientific knowledge in these areas, or less reliably, since the sample is smaller, by comparing notes with friends and relatives who have children. Intelligent parents, however, realize that the particular setting of each family is unique, and there can be no rigid general rules. They use general information only as a guide in making decisions and solving problems. For example, they will need specific suggestions for problems such as speech defects or backwardness in learning to walk or control of bodily functions. In the more general sense, though, problems of upbringing are recognized to be problems of relationships within the individual family, the first necessity being a secure emotional background with parents who are united in their attitude to their children. All parents have to solve the problems of freedom and discipline. The younger the child, the more readily the mother give in to his demands to avoid disappointing him. She knows that if his energies are not given an outlet, her childs continuing development may be warped. An example of this is the young childs need to play with the mud and sand and water. A child must be allowed to enjoy this “messy” but tactile stage of discovery before he is ready to go on to the less physical pleasures of toys and books. Similarly, throughout life, each stage depends on the satisfactory completion of the one before. Where one stage of child development has been left out, or not sufficiently experienced, the child may have to go back and capture the experience of it. A good home makes this possible-for example by providing the opportunity for the child to play with a clockwork car or toy railway train up to any age if he still needs to do so. This principle, in fact, underlies all psychological treatment of children in difficulties with their development, and is the basis of work in child clinics. The beginnings of discipline are in the nursery. Even the youngest baby is taught by gradual stages to wait for food, to sleep and to wake at regular intervals and so on. If the child feels the world around him is a warm and friendly one, he slowly accepts its rhythm and accustoms himself to conforming to its demands. Learning to wait for things, particularly for food, is a very important element in upbringing, and is achieved successfully only if too great demands are not made before the child can understand them. Every parent watches eagerly the childs acquisition of each new skill-the first spoken words, the first independent steps, or the beginning of reading and writing. It is often tempting to hurry the child beyond his natural learning rate, but this can set up dangerous feelings of failure and states of anxiety in the child. This might happen at any stage. A baby might be forced to us a toilet too early, a young child might be encouraged to learn to read before he knows the meaning of the words he reads. On the other hand, though, if a child is left alone too much, or without any learning opportunities, he loses his natural zest for life and his desire to find out new things for himself. Learning together is a fruitful source of relationship between children and parents. By playing together, parents learn more about their children and children learn more from their parents. Toys and games which both parents and children can share are an important means of achieving this cooperation. Building block toys and jigsaw puzzles and crosswords are good examples. Parents vary greatly in their degree of strictness and indulgence towards their children. Some may be especially strict in money matters; others are severe over times of coming home at night, punctuality for meals or personal cleanliness. In general, the controls imposed represent the needs of the parents and the values of the community as much as the childs own happiness and well-being. As regards the development of moral standards in the growing child, consistency is very important in parental teaching. To forbid a thing one day and excuse it the next is no foundation for