单选题People can (not) but feel (puzzling), for they (simply cannot) understand how he (could have made) such a stupid mistake. A. not B. puzzling C. simply D. could have made

单选题Of all the family members, grandparents are probably the least valued. They are just the people who have always been around. They make a fuss over the children in the family, show off to their friends the achievements of this child or that child, and show countless pictures of new babies. Grandfathers can fix anything, and grandmothers always have homemade biscuits around. When you are small, it's fun to stay with your grandparents because they always let you do things you can't do at home, and, of course, they buy you things. They are always able to babysit because they don't go out much and actually prefer to see their grandchildren. They are usually good for a small loan now and then that doesn't need to be paid back because they turn it into a gift. You respectfully listen to their advice but don't thank them politely for what they do for you, and then don't call or visit them until you need something else. And, of course, you never tell them how dear they are to you because they know how you feel about them anyway. Then all of a sudden, they are no longer there to do the things that only grandparents can do, and you find yourself wishing that you had told them what they meant to you as people and not just as grandparents.

单选题Specialization can be seen as a response to the problem of an increasing accumulation of scientific knowledge. By splitting up the subject matter into smaller units, one man could continue to handle the information and use it as the basis for further research. But specialization was only one of a series of related developments in science affecting the process of communication. Another was the growing professionalisation of scientific activity. No clear-cut distinction can be drawn between professionals and amateurs in science: exceptions can be found to any rule. Nevertheless, the word "amateur" does carry a connotation that the person concerned is not fully integrated into the scientific community and, in particular, may not fully share its values. The growth of specialization in the nineteenth century, with its consequent requirement of a longer, more complex training, implied greater problems for amateur participation in science. The trend was naturally most obvious in those areas of science based especially on a mathematical or laboratory training, and can be illustrated in terms of the development of geology in the United Kingdom. A comparison of British geological publications over the last century and a half reveals not simply an increasing emphasis on the primacy of research, but also a changing definition of what constitutes an acceptable research paper. Thus, in the nineteenth century, local geological studies represented worthwhile research in their own right; but, in the twentieth century, local studies have increasingly become acceptable to professionals only if they incorporate, and reflect on, the wider geological picture. Amateurs, on the other hand, have continued to pursue local studies in the old way. The overall result has been to make entrance to professional geological journals harder for amateurs, a result that has been reinforced by the widespread introduction of refereeing, first by national journals in the nineteenth century and then by several local geological journals in the twentieth century. As a logical consequence of this development, separate journals have now appeared aimed mainly towards either professional or amateur readership. A rather similar process of differentiation has led to professional geologists coming together nationally within one or two specific societies, whereas the amateurs have tended either to remain in local societies or to come together nationally in a different way. Although the process of professionalisation and specialization was already well under way in British geology during the nineteenth century, its full consequences were thus delayed until the twentieth century. In science generally, however, the nineteenth century must be reckoned as the crucial period for this change in the structure of science.

单选题Mr. Brown was at the theatre. He had got his ticket at the moment, so he had not been ahle to choose his seat. He now found that he was in the middle of a group of American la- dies, some of them middle-aged and some of them quite old. They clearly all knew each other well, as before the curtain went up on the play they had come to see, they all talked and joked a lot together. The lady sitting on Mr. Brown's left, who was about sixty years old, seemed to be the happiest and the most interesting of the American group, and after the first act of the play, she apologized to him for the noisiness of her friends. He answered that he was very glad to see American ladies so really enjoying their visit to England, and so they had a friendly talk. Mr. Brown's neighbour explained what they doing there. "You know, I have known these ladies all my life," she said. "We all grew up together back in our hometown in the United States. They have all lost their husbands~ and call themselves the Merry Widows. It is a sort of club, you know. They go to a foreign country every summer or two and have a lot of fun. They always go everywhere together. I have wanted to join their club for a long time, but I was not able to become a member until the spring of this year./

单选题The reforms are motivated by a ______ concern for the unemployed.

单选题The potential of closed-circuit television and other electronic teaching tools is so great that it is inspiring to imagine "the school of tomorrow". Televised lesson will be given in a central building having perhaps four or five master studios. The lesson will be carried out into classrooms all over a city, or even an entire country. After a televised lesson has been given, the classroom teacher will take over for the allimportant "follow-up" period. The students will ask any troublesome questions, and difficult points will be cleared up through discussion. The teacher in the classroom will have additional electronic tools. On the teacher"s desk, the traditional bright red apple will have been replaced by a multiple-control panel (控制板) and magnetic tape players. The tape machines will run prerecorded lessons which pupils will follow by headphones. The lesson will be specifically connected closely to the student"s levels of ability. For instance, while the class as a whole studies history, each student will receive an individual history lesson directed to his particular level of ability. Should questions arise, the students will be able to talk directly to the teacher on individual "intercoms" (对讲装置) without disturbing the rest of the class. In this way, the teacher will be able to conduct as many as three classes at the same time.

单选题The molecules of carbon dioxide in the Earth"s atmosphere affect the heat balance of the Earth by acting as a one-way screen. Although these molecules allow radiation at visible wavelengths, where most of the energy of sunlight is concentrated, to pass through, they absorb some of the longer-wavelength , infrared emissions radiated from the Earth"s surface, radiation that would otherwise be transmitted back into space. For the Earth to maintain a constant average temperature, such emissions from the planet must balance incoming solar radiation. If there were no carbon dioxide in the atmosphere, heat would escape from the Earth much more easily. The surface temperature would be so much lower that the oceans might be a solid mass of ice. Today, however, the potential problem is too much carbon dioxide. The burning of fossil fuels and the clearing of forests have increased atmospheric carbon dioxide by about 15 percent in the last hundred years, and we continue to add carbon dioxide to the atmosphere. Could the increase in carbon dioxide cause a global rise in average temperature, and could such a rise have serious consequences for human society? Mathematical models that allow us to calculate the rise in temperature as a function of the increase indicate that the answer is probably yes. Under present conditions a temperature of - 18°C can be observed at an altitude of 5 to 6 kilometers above the Earth.Below this altitude (called the radiating level) , the temperature increasesby about 6°C per kilometer approaching the Earth"s surface, where the average temperature is about 15°C. An increase in the amount of carbon dioxide means that there are more molecules of carbon dioxide to absorb infrared radiation. As the capacity of the atmosphere to absorb infrared radiation increases, the radiating level and the temperature of the surface must rise. One mathematical model predicts that doubling the atmospheric carbon dioxide would raise the global mean surface temperature by 2.5°C： This model assumes that the atmosphere"s relative humidity remains constant and the temperature decreases with altitude at a rate of 6. 5 °C per kilometer. The assumption of constant relative humidity is important, because water vapor in the atmosphere is another efficient absorber of radiation at infrared wavelengths. Because warm air can hold more moisture than cool air, the relative humidity will be constant only if the amount of water vapor in the atmosphere increases as the temperature rises. Therefore, more infrared radiation would be absorbed and reradiated back to the Earth"s surface. The resultant warming at the surface could be expected to melt snow and ice, reducing the Earth"s reflectivity. More solar radiation would then be absorbed, leading to a further increase in temperature.

单选题"The world"s environment is surprisingly healthy. Discuss." If that were an examination topic, most students would tear it apart, offering a long list of complaints: from local smog (烟雾) to global climate change, from the felling (砍伐) of forests to the extinction of species. The list would largely be accurate, the concern legitimate. Yet the students who should be given the highest marks would actually be those who agreed with the statement. The surprise is how good things are, not how bad. After all, the world"s population has more than tripled during this century, and world output has risen hugely, so you would expect the earth itself to have been affected. Indeed, if people lived, consumed and produced things in the same way as they did in 1900 (or 1950, or indeed 1980), the world by now would be a pretty disgusting place, smelly, dirty, toxic and dangerous. But they don"t. The reasons why they don"t, and why the environment has not been ruined, have to do with prices, technological innovation, social change and government regulation in response to popular pressure. That is why today"s environmental problems in the poor countries ought, in principle, to be solvable. Raw materials have not run out, and show no sign of doing so. Logically, one day they must: the planet is a finite place. Yet it is also very big, and man is very ingenious. What has happened is that every time a material seems to be running short, the price has risen and, in response, people have looked for new sources of supply, tried to find ways to use less of the material, or looked for a new substitute. For this reason prices for energy and for minerals have fallen in real terms during the century. The same is true for food. Prices fluctuate, in response to harvests, natural disasters and political instability; and when they rise, it takes some time before new sources of supply become available. But they always do, assisted by new farming and crop technology. The long term trend has been downwards. It is where prices and markets do not operate properly that this benign (亲戚) trend begins to stumble, and the genuine problems arise. Markets cannot always keep the environment healthy. If no one owns the resource concerned, no one has an interest in conserving it or fostering it: fish is the best example of this.

单选题 One of the basic characteristics of capitalism is the private ownership of the major means of production-capital. The ownership of large amounts of capital can bring {{U}}(61) {{/U}} profits, as well as economic and political power. Some recent theorists, {{U}}(62) {{/U}} have argued that our society has moved to a new stage of {{U}}(63) {{/U}} that they call "postindustrial" society. One important change in such society is that the ownership of {{U}}(64) {{/U}} amounts of capital is no longer the only or even the most important {{U}}(65) {{/U}} of profits and influence; knowledge as well as {{U}}(66) {{/U}} capital brings profits and influence. There are many {{U}}(67) {{/U}} with the thesis above, not the least of {{U}}(68) {{/U}} is that wealthy capitalists can buy the experts and knowledge they need to keep their profits and influence. But this does not {{U}}(69) {{/U}} the importance of knowledge in an advanced industrial society, as the {{U}}(70) {{/U}} of some new industries indicates. {{U}}(71) {{/U}}, genetic engineering and the new computer technology have {{U}}(72) {{/U}} many new firms and made some scientists quite rich. In {{U}}(73) {{/U}} with criticism of the postindustrial society thesis, however, it must also be {{U}}(74) {{/U}} that those already in control of huge amounts of capital (i. e. , major corporations) soon {{U}}(75) {{/U}} to take most profits in these industries based on new knowledge. Moving down from the level of wealth and power, we still find knowledge increasingly {{U}}(76) {{/U}}. Many new high-tech jobs are being created at the upper-skill, low-paying service {{U}}(77) {{/U}}. Something like a caste line is emerging centered around knowledge. Individuals who fall too far behind in the {{U}}(78) {{/U}} of knowledge at a young age will find it almost impossible to catch up later, no matter how hard they try, Illiteracy in the English language has been a severe {{U}}(79) {{/U}} for many years in the United States, but we are also moving to the point when computer illiteracy will hinder many more people and {{U}}(80) {{/U}} them to a life of low-skill and low paid labor.

单选题The effect of the shock will soon ______.

单选题You look pale, What's wrong ______ you?A. withB. byC. onD. at

单选题We should never {{U}}underestimate{{/U}} influence we can have on the children we love.

单选题______, I shall still have to work in the garden. A. As the sun is hot B. Hot as the sun is C. As hot the sun is D. Hot as is the sun

单选题The study of how words are combined to form sentences is called ______.

单选题She has bought a pair of glasses, which she can never ______ when reading books. A. do with B. do up C. do away D. do without

单选题Be careful! Don’t ______ your drink on the table.