单选题Mr. John had given no ______ that he was intending to resign.

单选题All was confusion around him; ______ he remained calm and unruffled.

单选题According to some scientists, migratory birds should be able to withstand the winter. A bird"s feathery coat is good insulation against the cold. Because a bird is warm-blooded, its body temperature always remains constant, even if the temperature of its surroundings changes. The factors that trigger migratory behavior in birds are difficult to explain. This behavior seems to be instinctive, not learned. For example many northern species leave their summer homes while the weather is still warm and the food supply plentiful. Young arctic terns born at the arctic breeding grounds will take off with the flock for distant lands they have never seen. Bird migrations are probably regulated by the glandular system. Scientists suspect that the changing length of the day is the factor that triggers migratory behavior. In an experiment, migratory birds were kept in artificially lighted rooms. It was found that if periods of darkness were lengthened proportionately, the glands of the birds became active. These glands secrete hormones, which are chemicals that control numerous body functions. Shorter periods of daylight seem to change the hormone balance of birds, so that they retain more fat. This stored fat that provides the energy for a long flight. The same experiment revealed that the birds became more excited as the artificial night was lengthened. It is probably no coincidence that most flocks begin their migratory flights during the night.

单选题If he hadn"t stood under the ladder to catch you when you fell, you ______ here now.

单选题The gift was sent by ______. A. a friend of my father B. my father friend C. my father friend's D. a friend of my father's

单选题The country"s stability must therefore be based on the reconciliation of the relationships between different ethnic groups

单选题______ Why didn't you buy the camera you had longed for? ______ I had planned to, but I was 50 Yuan ______. A. fewer B. less C. cheap D. short

单选题Biologists have {{U}}ascertained{{/U}} that specialized cells convert chemical energy into mechanical energy. A. determined B. argued C. hypothesized D. griped

单选题In their productions, choreographers of modern dance have introduced humor, protested social injustice, and ______ psychological problems.

单选题You hear me______! This is important. Don"t treat it______a joke.

单选题Passage One The Roman language served as the first model for answering the question. Even to someone with no knowledge of Latin, the similarities among Roman languages would have made it natural to suggest that they were derived from a common ancestor. On the assumption that the shared characteristic of these languages came from the common ancestor, it would have been possible to reconstruct many of the characteristics of the original common language. In much the same way it became clear that the branches of the Indo-European family could be studied and a hypothetical family tree constructed, reading back to a common ancestor. This is the tree approach. The basic process represented by the tree model is one of divergence: when languages become isolated from one another, they differ increasingly, and dialects gradually become different until they become separate languages. Divergence is by no means the only possible tendency in language evolution. Johannes Schmidt introduced a "wave" model, in which linguistic changes were like waves, eventually leading to convergence; that is, growing similarity among languages that were initially quite different. Today, however, most linguists think primarily in terms of familytrees. It is necessary to construct some models of how language change might occur according to a process-based view. There are four main classes of models. The first is the process of initial colonization, by which an uninhabited territory becomes populated; its language naturally becomes that of the colonizers. Second are processes of divergence, such as the linguistic divergence arising from separation or isolation mentioned above in relation to early models of the Indo-European languages. The third group of models is based on processes of linguistic convergence. The wave model, formulated by Schmidt in the 1870's, is an example, but convergence methods have not generally found favor among linguists. Now, the slow and rather static operation of these processes is complicated by another factor: linguistic replacement. That factor provides the basis for a fourth class of models, in many areas of the world the languages initially spoken by the indigenous people have come to be replaced, fully or partially, by languages spoken by people coming from outside. Were it not for this large complicating factor, the world's linguistic history could be faithfully described by the initial distribution of Homo Sapiens, followed by the gradual workings of divergence and convergence. So linguistic replacement also has a key role to play in explaining the origins of the Indo-European languages.

单选题Marks and Spencer admits that trading in recent weeks has shown ______ improvement.

单选题Passage 2 Since the late 1970's in the face of a severe loss of market share in dozens of industries, manufacturers in the United States have been trying to improve productivity—and therefore enhance their international competitiveness—through cost-cutting programs. (Cost-cutting here is defined as raising labor output while holding the amount of labor constant.) However, from 1978 through 1982, productivity—the value of goods manufactured divided by the amount of labor input—did not improve; and while the results were better in the business upturn of the three years following, they ran 25 percent lower than productivity improvements during earlier, post-1945 upturns. At the same time, it became clear that the harder manufactures worked to implement cost-cutting, the more they lost their competitive edge. With this paradox in mind, I recently visited 25 companies; it became clear to me that the cost-cutting approach to increasing productivity is fundamentally flawed. Manufacturing regularly observes a "40, 40, 20" rule. Roughly 40 percent of any manufacturing-based competitive advantage derives from long-term changes in manufacturing structure (decisions about the number, size, location, and capacity of facilities) and in approaches to materials. Another 40 percent comes from major changes in equipment and process technology. The final 20 percent rests on implementing conventional cost-cutting. This rule does not imply that cost-cutting should not be tried. The well-known tools of this approach—including simplifying jobs and retraining employees to work smarter, not harder—do produce results. But the tools quickly reach the limits of what they can contribute. Another problem is that the cost-cutting approach hinders innovation and discourages creative people. As Abernathy's study of automobile manufacturers has shown, an industry can easily become prisoner of its own investments in cost-cutting techniques, reducing its ability to develop new products. And managers under pressure to maximize cost-cutting will resist innovation because they know that more fundamental changes in processes or systems will wreak havoc with the results on which they are measured. Production managers have always seen their job as one of minimizing costs and maximizing output. This dimension of performance has until recently sufficed as a basis of evaluation, but it has created a penny-pinching, mechanistic culture in most factories that has kept away creative managers. Every company I know that has freed itself from the paradox has done so, in part, by developing and implementing a manufacturing strategy. Such a strategy focuses on the manufacturing structure and on equipment and process technology. In one company a manufacturing strategy that allowed different areas of the factory to specialize in different markets replaced the conventional cost-cutting approach; within three years the company regained its competitive advantage. Together with such strategies, successful companies are also encouraging managers to focus on a wider set of objectives besides cutting costs. There is hope for manufacturing, but it dearly rests oil a different way of managing.

单选题When it was published in 1959, Robert Frank's book, The American, ______ hostility in the United States.

单选题When ______, many racists cannot give a logical reason for their attitudes towards other racial groups.

单选题I know he failed his last test, but really he's ______ stupid. A. something but B. anything but C. nothing but D. not but

单选题Penny's ______ speech given at the state competition won her the first prize.

单选题Following are comments about the behavior that people in Korea usually expect it in various social ______.

单选题TEXT D Got milk? If you do, take a moment to ponder the true oddness of being able to drink milk after you're a baby. No other species but humans can. And most humans can't either. The long lists of food allergies some people claim to have can make it seem as if they're just finicky eaters trying to rationalize likes and dislikes. Not so. Eggs, peanuts, tree nuts, fish, shellfish soy and gluten all can wreak havoc on the immune system of allergic individuals, even causing a deadly reaction called anaphylaxis. But those allergic reactions are relatively rare, affecting an estimated 4% of adults. Milk's different. There are people who have true milk allergies that can cause deadly reactions. But most people who have bad reactions to milk aren't actually allergic to it, in that it's not their immune system that's responding to the milk. Instead, people who are lactose intolerant can't digest the main sugar-lactose-found in milk. In normal humans, the enzyme that does so-lactase-stops being produced when the person is between two and five years old. The undigested sugars end up in the colon, where they begin to ferment, producing gas that can cause cramping, bloating, nausea, flatulence and diarrhea. If you're American or European it's hard to realize this, but being able to digest milk as an adult is one weird genetic adaptation. It's not normal. Somewhat less than 40% of people in the world retain the ability to digest lactose after childhood. The numbers are often given as close to 0% of Native Americans, 5% of Asians, 25% of African and Caribbean peoples, 50% of Mediterranean peoples and 90% of northern Europeans. Sweden has one of the world's highest percentages of lactase tolerant people. Being able to digest milk is so strange that scientists say we shouldn't really call lactose intolerance a disease, because that presumes it's abnormal, instead, they call it lactase persistence, indicating what's really weird is the ability to continue to drink milk. There's been a lot of research over the past decade looking at the genetic mutation that allows this subset of humanity to stay milk drinkers into adulthood. A long-held theory was that the mutation showed up first in Northern Europe, where people got less vitamin D from the sun and therefore did better if they could also get the crucial hormone (it's not really a vitamin at all) from milk. But now a group at University College London has shown that the mutation actually appeared about 7, 500 years ago in dairy farmers who lived in a region between the central Balkans and central Europe, in what was known as the Funnel Beaker culture. The paper was published this week in PLOS Computational Biology. The researchers used a computer to model the spread of lactase persistence, dairy farming, other food gathering practices and genes in Europe. Today, the highest proportion of people with lactase persistence live in Northwest Europe, especially the Netherlands, Ireland and Scandinavia. But the computer model suggests that dairy farmers carrying this gene variant probably originated in central Europe and then spread more widely and rapidly than non-dairying groups. Author Mark Thomas of University College London's dept of Genetics, Evolution and Environment says, "In Europe, a single genetic change.., is strongly associated with lactase persistence and appears to have people with it a big survival advantage. " The European mutation is different from several lactase persistence genes associated with small populations of African peoples who historically have been cattle herders. Researchers at the University of Mary land identified one such mutation among Nilo-Saharan-speaking peoples in Kenya and Tanzania. That mutation seems to have arisen between 2,700 to 6, 800 years ago. Two other mutations have been found among the Beja people of northeastern Sudan and tribes of the same language family in northern Kenya.

单选题So involved with their computers______that leaders at summer computer camps often have to force them to break for sports and games.