Dental Health Decay is not the only disease that can cause tooth loss. Another serious disease affects the gums, the tissue that surrounds the teeth. It is also caused by bacteria. If the bacteria are not removed every day, they form a substance that stays on the teeth. The substance is known as plaque. At first, the gums appear to be swollen, and may bleed when the teeth are brushed. This can lead to serious infection of the tissue around the teeth. The infection may damage the bone that supports the teeth and cause tooth loss and other health problems. Studies have found that people with severe gum disease have an increased risk of developing heart disease, diabetes and stroke. Gum disease can be treated by a special dentist called a periodontist. Periodontists are trained to repair the gum areas that have been damaged. This can be painful and costly. Dental health experts say the best thing to do is to stop gum disease before it starts. The way to do this is to clean the teeth every day. People also should use dental floss to remove plaque from between the teeth. Most experts also agree that another way to prevent tooth and gum problems is to eat foods high in calcium and vitamins and low in sugar. Scientists continue to develop better dental treatments and equipment. Improved technology may change the way people receive dental treatment in the future. For example, dentists are now suing laser light to treat diseased gums and teeth. Dentists use computer technology to help them repair damaged teeth. Researchers have developed improved methods to repair bone that supports the teeth. And genetic research is expected to develop tests that will show the presence of disease causing bacteria in the mouth. Such increased knowledge about dental diseases and ways to prevent them has improved the health of many people. Yet problems remain in some areas. In industrial countries, minorities and other groups have a high level of untreated dental disease. In developing countries, many areas do not have even emergency care services. The World Health Organization says people in countries in Africa have the most tooth and gum problems. World Health Organization experts say the dental health situation is different for almost every country in the world. As a result, it has developed oral health programs separately for each area. The WHO oral health program is mainly for people living in poor areas. It provides them with information about mouth diseases and health care. It also studies preventive programs using fluoride in water, salt, mild and toothpaste. And it explores ways to include dental health in national health care systems. Many governments and other organizations provide help, so people can get needed dental health services. But dental health professionals say people should take good care of their teeth and gums. They say people should keep their teeth as clean as possible. They should eat foods high in calcium and fiber. These include milk products, whole grain breads and cereals, vegetables, fruits, beans and nuts. Recent studies have shown that eating nuts can help slow the production of plaque on the teeth. Experts say these activities will help everyone improve their dental health throughout their lives.
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Is More Growth Really Better? A number of writers have raised questions about the desirability of faster economic growth as an end in itself, at least in the wealthier industrialized countries. Yet faster growth does mean more wealth, and to most people the desirability of wealth is beyond question. “I’ve been rich and I’ve been poor—and I can tell you, rich is better,” a noted stage personality is said to have told an interviewer, and most people seem to have the same attitude about the economy as a whole. To those who hold this belief, a healthy economy is one that is capable of turning out vast quantities of shoes, food, cars, and TV sets. An economy whose capacity to provide all these things is not expanding is said to have succumbed to the disease of stagnation. Economists from Adam Smith to Karl Marx saw great virtue in economic growth. Marx argued that capitalism, at least in its earlier historical stages, was a vital form of economic organization by which society got out of the rut in which the medieval stage of history had trapped it. Marx believed that “the development of the productive powers of society... alone can form the real basis of a higher form of productive powers of society”. Marx went on to tell us that only where such great productive powers have been unleashed can one have “a society in which the full and free development of every individual forms the ruling principle.” In other words, only a wealthy economy can afford to give all individuals the opportunity for full personal satisfaction through the use of their special abilities in their jobs and through increased leisure activities. Yet the desirability of further economic growth for a society that is already wealthy has been questioned on grounds that undoubtedly have a good deal of validity. It is pointed out that the sheer increase in quantity of products has imposed an enormous cost on society in the form of pollution, crowding, proliferation of wastes that need disposal, and debilitating psychological and social effects. It is said that industry has transformed the satisfying and creative tasks of the artisan into the mechanical and dehumanizing routine of the assembly line. It has dotted our roadsides with junkyards, filled our air with smoke, and poisoned our food with dangerous chemicals. The question is whether the outpouring of frozen foods, talking dolls, radios, and headache remedies is worth its high cost to society. As one well-known economist put it: The continued pursuit of economic growth by Western Societies is more likely on balance to reduce rather than increase social welfare... Technological innovations may offer to add to men’s material opportunities. But by increasing the risks of their obsolescence it adds also to their anxiety. Swifter means of communications have the paradoxical effect of isolating people; increased mobility has led to more hours commuting; increased automobilization to increased separation; more television to less communication. In consequence, people know less of their neighbors than ever before. Virtually every economist agrees that these concerns are valid, though many question whether economic growth is their major cause. Nevertheless, they all emphasize that pollution of air and water, noise and congestion, and the mechanization of the work process are very real and very serious problems. There is every reason for society to undertake programs that grapple with these problems. 11
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Don’t Blame DNA The really critical implication of the discovery still lies with the door that geneticists have opened on the environmental influences of our behaviour, our personalities and our health, 1 and with the critical blow it strikes on the idea of biological determinism. For the past decade, the public has witnessed a rising epidemic of tales of discoveries of genes that dispose humanity to homosexuality, to alcoholism, to political persuasion, to running ability, and to artistic taste. But even before yesterday’s revelations by Venter, scientists had stopped believing in the gay gene. Yet belief in its existence still persists among the public. The assault on biological determinism that geneticists have now triggered will be timely, and will prove that human nature is a lot more complex and intriguing than determinists have given it credit for. Even more importantly, the discovery has critical implications for our understanding of idea of free will. It has become increasingly fashionable for individuals particularly in the United States to blame actions and crimes on the influence of their genes. Consider the following story. A young American woman, Glenda Sue Caldwell, was convicted of killing her child and was jailed for life. Only later did she begin to display the symptoms of Huntington’s Disease, an inherited brain disorder that produces horrific delusions and uncontrolled movements. Claiming she was a victim of her genes, the woman was cleared on appeal. Since then, several other U.S. defendants accused of violent crimes have argued that they too were innocent victims of their genes. They were not responsible for their actions. Their genes were. None of these people have yet succeeded in persuading courts of their innocence and their genes’ guilt. Most lawyers felt such an outcome was nevertheless inevitable. In other words, genetic predestination could soon have been used to excuse murder or robbery—if it had not been for this discovery that we lack the genes to thus dispose us! Kevin Davies is the author of The Sequence, a story of the human genome race11. He said, “There has been a recent study on perfect pitch, the ability to know the absolute pitch of a musical note, that strongly suggests that is acquired through the inheritance of a single gene.” “That may sound like a clear-cut piece of biological determinism. However, there is a crucial corollary: you have to be exposed to early musical training for the ability to materialize. 13 In other words, even in seemingly simple inherited abilities, nurture has a role to play.” And then there is the case quoted by Venter. “Everyone talks about a gene for this and that. But it is not like that. Take the example of colon cancer. People say there is a gene that predisposes us to the disease. And certainly it runs in families. It is caused by an inherited weakness in one gene that controls DNA repair in other genes. 14 But that gene is found in cells in every part of the body. However, it is only the colon where we find all sorts of toxins and bacteria that provide the harsh circumstances that cause that gene to finally break down and for cancer to spread.” In short, it is not a colon cancer gene but a gene that affects our ability to respond to the environment. And that, is what human nature is all about.
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Pollution and Ecocrisis The problem of pollution is also of great social concern. Continued population increase, accompanied by a rise in the level of living standards, not only threatens to exhaust American resources but pollutes the environment to such an extent that production in the thickly settled area is impossible without damaging the health of the local residents. Smog, once an urban annoyance, is now recognized as a health risk, and the automobile has been pinpointed as the principal culprit. Heavy industries have been blamed for river, soil, air, noise and visual pollutions. DDT and other chemical remedies have been doing more ecological harm than the good that they may have brought along. Several decades ago, Americans dumped raw sewage into rivers and many industrial plants are now still dumping chemical pollutants into lakes, rivers and oceans. Oceans used to be and are still being considered to be a reserve of seafood. Today, after the oceans have become the home of all pollutants, this use of the oceans is being reduced at an alarming rate. The worst pollution threat is concentrated in and near large cities. There the people-made pollutants increasingly surpass the ability of air and water to dilute (冲淡；稀释) the contaminants (污染物) to safe levels. The natural ecological cycle depends on plants, which absorb some pollutants and release oxygen to the air. But near large cities, natural vegetation becomes scarce, and introduced trees, ornamental shrubs and gardens are far from adequate in absorbing motor vehicle and industrial air pollutants. Finally, some pollutants, most notably atomic waste, may continue to contaminate air, land, and water for thousands of years. Therefore, ecocrisis—ecocatastrophe or ecocide—has been for some time one of the major concerns of not only the ecoactivists and environmentalists, but of many scientists of other fields and the government authorities of many countries as well. Last but not least, there is the question of whether the people will eventually be able to solve all these problems. The American continent is a wealthy land inhabited by many able and well- educated people. There today, people have originated a life-style which is known to the world as being characteristic of a society of consumption—a life-style based on the prodigal (挥霍浪费的) use of material goods. They are using up many times their share of the earth’s resources at a rate unparalleled in history. And I am sorry to say that this life-style of American has been copied by the people of many developed countries, leading to the greatest problem of the modem world as a whole. So I must ask: Are the Americans apt enough to cooperate with other peoples to prevent over-population, resource exhaustion, the catastrophe of pollution and the wanton waste of wealth — problems which are basic to the solution of many outstanding economic, social and political problems? Only time will tell.
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Oxford When language learners arrive in Oxford, many ask where the university is, thinking that they will be shown just one building. It’s up to their teachers to explain that Oxford university is made up of a collection of many different colleges and institutions, each with its own history and characteristics. There are many other surprises that learners discover about the city and its university. Katie Jennings is a social organizer at King’s St Joseph’s Hall in East Oxford, and it is her job to organize activities for learners outside of lesson time. She says many learners are surprised to discover that Oxford is a home to a wide variety of nationalities and ethnic groups, and one of the most popular social events is a night out at one of the town’s Latin American dance clubs. After a day spent learning English and absorbing the ancient atmosphere of the university, learners can samba the night away. The city also has a thriving Asian community, and the sight of women in saris is as common in Oxford’s streets as academics in gowns and mortarboards. There is also a mouth-watering selection of Asian restaurants serving curries, as well as shops stocked with exotic vegetables and fruits. The city has attracted such a diverse population not only because of the university, but also because it is an important industrial centre which is known for car manufacturing among other things. In spite of large industrial areas, the old of the city centre has remained surprisingly intact. Carmel Engin, who teaches at the Lake School, says many learners are surprised to find that the city is free from the usual high-rise modern buildings. “From the centre of Oxford, you can see green hills in the distance, and this will make learners deeply feel that they are in a small, friendly town, but not just another modern metropolis.” Some learners will be tempted to explore those green hills—Oxford is surrounded by some of the most beautiful countryside in southern England—but, as Engin admits, with so much to do and see in the city, few learners find the time, to explore its surroundings.
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An Early History of Australia Before the arrival of European settlers, Aboriginal and Tortes Strait (托雷斯海峡) Islander peoples inhabited most areas of the Australian continent. Each people spoke one or more of hundreds of separate languages, with lifestyles and religious and cultural traditions that differed according to the region in which they lived. Adaptable and creative, with simple but highly efficient technology, Indigenous Australians had complex social systems and highly developed traditions reflecting a deep connection with the land and environment. Asian and Oceanic people had contact with Australia’s Indigenous peoples for thousands of years before the European expansion into the Eastern Hemisphere. Some formed substantial relationships with communities in northern Australia. In 1606, the Spanish explorer Luis Vaez de Torres sailed through the strait that separates Australia and Papua New Guinea (巴布亚新几内亚). Dutch explorers charted the north and west coasts and found Tasmania. The first British explorer, William Dampier, landed on the northwest coast in 1688. But it was not until 1770 that his countryman, Captain James Cook, on the Endeavour, extended a scientific voyage to the South Pacific in order to chart the east coast of the continent that had become known as New Holland, and claimed it for the British Crown. The American war of independence shut off that country as a place to transport convicts, requiring Great Britain to establish a new penal colony. Sir Joseph Banks, the President of the Royal Society, had sailed as a naturalist (博物学家) with Captain Cook, and suggested Australia for this purpose. The First Fleet of 11 ships arrived at Botany Bay in January 1788. Governor Phillip preferred Sydney Harbor and the date he landed in the Harbor,26 January, is now commemorated as Australia Day. The First Fleet carded 1,500 people, half of them convicts. Robert Hughes’ The Fatal Shore (1987) is a classic book on the convict system. Hughes suggests that the penal system had lasting effects on Australian society. About 160,000 convicts were sent to the Australian continent over the next 80 years. The wool industry and the gold rushes of the mid-19th century provided an impetus to free settlement. Scarcity of labor, the vastness of the bush and new wealth based on farming, mining and trade all contributed to the development of uniquely Australian institutions and sensibilities. At the time of European settlement in 1788 it is estimated there were at least 300,000 Aboriginals and Torres Strait Islanders in Australia. European settlement involved the displacement and dispossession of Indigenous peoples. It disrupted traditional land management practices and introduced new plants and animals into fragile Australian ecosystems.