单选题As a salesman, he works on a ______ basis, taking 10% of everything he sells.

单选题Improvements in labor productivity 56 increase wages and salaries. Wages and salaries 57 about 75 percent of all income in the United States. 58 , labor productivity is the major 59 of this (and all other) nations' living standards. If labor productivity improves because of an advance in technology, the 60 of output increases 61 the need for additional labor. The dollar value of all goods increases 62 , which implies that consumers ultimately receive more income. Entrepreneurs have a profit 63 to increase labor productivity. They do so by providing their workers with better equipment and creating more efficient ways for their workers to use that equipment. Entrepreneurs also have an incentive to discover new products that are more highly valued 64 to their cost of production. Some of the largest increases in productivity occur 65 major technological advancements. The steam engine and the internal combustion engine are two examples. The advances in the computer industry have been 66 phenomenal. Advances in technology depend 67 on businesses making 68 investment in new technology and new products. A major issue in today's economy is 69 businesses are doing this and what incentives are being provided by the government to companies to encourage investment. Another issue is whether labor productivity in the United States has 70 other countries. There have also been 71 increases in productivity in our agricultural 72 . Because of the increased use of chemicals, the 73 per acre are many times greater than they were 100 years ago, and consequently, 74 Americans now 75 farming, yet agricultural output is the highest it has, ever been.

单选题Packed like sardines into sweaty, claustrophobic subway carriages, passengers can barely breathe, ______ move about freely.

单选题{{I}}Ⅱ. Directions: Read the following passage carefully and then explain in your own English the exact meaning of the numbered and underlined parts. Put your answers on AN-SWER SHEET 2.{{/I}} {{B}}Green Spaces in cities{{/B}} Where do children play? Years ago, any open field, any vacant lot, any group pf trees--these were the places where children played. As families left family farms, small towns, and the countryside, and moved into cities, the places for their children to play in became rarer. Children in the cities had few options, fewer choices of places to play. In fact, all people's lives change a lot when they move to the city. (51) {{U}}In cities, homes are built on top of one another--in enormous apartment buildings{{/U}}. (52) {{U}}The feeling of private space and ownership no longer exists in houses literally piled one on the other{{/U}}. Psychologists have been studying the changes people experience when they leave rural area and move into urban environments. On clear findings from their studies is that people need green spaces for better mental health. Children can play on paved playgrounds. That's true. However, they just don't have as much fun as children in small towns. (53) {{U}}Without grass and trees and bushes and, yes, dirt and mud to get dirtyin, children miss an important part of childhood{{/U}}. (54) {{U}}The human soul, it seems, needs to stay close to its roots{{/U}}. Adults can plant lots of things like bulbs in window boxes and large containers. (55) {{U}}However, tending window boxes isn't the same as being an amateur gardener and growing peas, tomatoes and salad greens in a backyard garden{{/U}}. The lack of green space is now recognized and understood as a problem.

单选题The multibillion-dollar fitness industry ______ fat profits from our hunger to look good.

单选题Doctors must inform ______ parents about the low odds of success in fertility treatments.

单选题{{B}}Passage Two{{/B}} The most interesting architectural phenomenon of the 1970's was the enthusiasm for refurbishing older buildings. Obviously, this was not an entirely new phenomenon. What is new is the wholesale interest in reusing the past, in recycling, in adaptive re- habilitation. A few trial efforts, such as Ghirardelli Square in San Francisco, proved their financial viability in the 1960's, but it was in the 1970's, with strong government support through tax incentives and rapid depreciation, as well as growing interest in ecology issues, that recycling became a major factor on the urban scene. One of the most comprehensive ventures was the restoration and transformation of Boston's eighteenth century Faneuil Hall and the Quincy Market, designed in 1824. This section had fallen on hard times, but beginning with the construction of a new city hall immediately adjacent, it has returned to life with the intelligent reuse of these fine old buildings under the design leadership of Benjamin Thompson. He has provided a marvelous setting for dining, shopping, professional offices, and simply walking. Butler Square, in Minneapolis, exemplifies major changes in its complex of offices, commercial space, and public amenities carved out of a massive pile designed in 1906 as a hardware warehouse. The exciting interior timber structure of the building was highlighted by cutting light courts through the interior and adding large skylights. San Antonio, Texas, offers an object lesson for numerous other cities combating urban decay. Rather than bringing in the bulldozers, San Antonio's leaders rehabilitated existing structures while simultaneously cleaning up the San Antonio River, which meanders through the business district.

单选题{{B}}Passage Six{{/B}} Caffeinated coffee may have an undeserved bad rap. A new study shows the decaffeinated variety may have harmful heart effects. The study showed that people who drank decaf had higher levels of a protein linked to heart disease risk compared with those who drank caffeinated coffee or no coffee. "But the differences were fairly small and there's probably no health threat from drinking a cup or two of any type of coffee a day," says researcher H. Robert Superko, MD. The research is the latest entry into a long line of scientific studies looking at whether coffee drinking can lead to heart disease. The participants were given premeasured bags of coffee to make in their coffee machines provided by researchers, They agreed to drink it black--no cream or sugar al-lowed. And they agreed to periodic blood tests so the researchers could keep track of exactly how much caffeine they drank. The 187 volunteers were assigned to one of three groups: no coffee, three to six cups a day of caffeinated coffee, or three to six cups of decaf. After three months, levels of apolipoprotein B (ApoB) were up significantly in the decaffeinated group while staying relatively unchanged in the other two groups. The amount of ApoB has been suggested in other studies to be a better predictor of cardio-vascular disease risk. There was one group for whom decaf appeared to be heart healthy: the overweight. For those who had body mass indexes (BMIs) of more than 25, drinking decaffeinated coffee boosted levels of HDL (high density lipoprotein) by about 50%. Among those with lower BMIs (who were not overweight), HDL dropped 30%. Elevated HDL is known to protect the heart. Here's also good news for people who love coffee: Drinking it doesn't seem to cause long-term high blood pressure, a study suggests. Caffeine is a well-known ingredient in both beverages, and has been shown to cause short-term increases in blood pressure. Previous data on coffee and hypertension is mixed. There's a common perception that its temporary effects on blood pressure mean an increased long-term risk, said Dr. Wolfgang Winkelmayer, the study's lead author. "We found strong evidence to refute that belief," the researchers wrote. There was even some evidence that people who drank lots of coffee--four or more daily cups of regular or decal--faced a slightly lower risk for developing high blood pressure than those who drank little or none. Winkelmayer said that might be because coffee has lots of antioxidants, substances that are thought to be helpful.

单选题The encouragement of children to achieve new skills ______.

单选题Most scholars agree that Isaac Newton, while formulating the laws of force and gravity and inventing the calculus in the late 1600s, probably knew all the science there was to know at the time. In the ensuing 350 years an estimated 50 million research papers and innumerable books have been published in the natural sciences and mathematics. The modern high school student probably now possesses more scientific knowledge than Newton did, yet science to many people seems to be an impenetrable mountain of facts. One way scientists have tried to cope with this mountain is by becoming more and more specialized. Another strategy for coping with the mountain of information is to largely ignore it. That shouldn"t come as a surprise. Sure, you have to know a lot to he a scientist, but knowing a lot is not what makes a scientist. What makes a scientist is ignorance. This may sound ridiculous, but for scientists the facts are just a starting place. In science, every new discovery raises 10 new questions. By this calculus, ignorance will always grow faster than knowledge. Scientists and laypeople alike would agree that for all we have come to know, there is far more we don"t know. More important, every day there is far more we know we don"t know. One crucial outcome of scientific knowledge is to generate new and better ways of being ignorant: not the kind of ignorance that is associated with a lack of curiosity or education but rather a cultivated, high-quality ignorance. This gets to the essence of what scientists do: they make distinctions between qualities of ignorance. They do it in grant proposals and over beers at meetings. As James Clerk Maxwell, probably the greatest physicist between Newton and Einstein, said, "Thoroughly conscious ignorance...is a prelude to every real advance in knowledge. " This perspective on science—that it is about the questions more than the answers— should come as something of a relief. It makes science less threatening and far more friendly and, in fact, fun. Science becomes a series of elegant puzzles and puzzles within puzzles— and who doesn"t like puzzles? Questions are also more accessible and often more interesting than answers; answers tend to be the end of the process, whereas questions have you in the thick of things. Lately this side of science has taken a backseat in the public mind to what I call the accumulation view of science—that it is a pile of facts way too big for us to ever hope to conquer. But if scientists would talk about the questions, and if the media reported not only on new discoveries but the questions they answered and the new puzzles they created, and if educators stopped trafficking in facts that are already available on Wikipedia—then we might find a public once again engaged in this great adventure that has been going on for the past 15 generations.

单选题From the passage, we can infer that "big bang" means______.

单选题Do you think it is late to ______ on a new career?

单选题Birds evolved during the great reptilian radiation of the Mesozoic era. Amniotic eggs and scales on the legs are just two of the reptilian features we see in birds. But modern birds look quite different from modern reptiles because of their feathers and other distinctive flight equipment. Characteristics of Birds Almost every part of a typical bird's anatomy is modified in some way that enhances flight. The bones have an internal structure that is honeycombed, making them strong but light. The skeleton of a frigate bird, for instance, has a wingspan of more than 2 meters but weighs only about 113 grams. Another adaptation reducing the weight of birds is the absence of some organs. Females, for instance, have only one ovary. Also, modern birds are toothless, an adaptation that trims the weight of the head. Food is not chewed in the mouth but ground in the gizzard, a digestive organ near the stomach.(Crocodiles also have gizzards, as did some dinosaurs.)The bird's beak, made of keratin, has proven to be very adaptable during avian evolution, taking on a great variety of shapes suitable for different diets. Flying requires a great expenditure of energy from an active metabolism. Birds are endothermic: they use their own metabolic heat to maintain a warm, constant body temperature. Feathers and, in some species, layers of fat provide insulation that enables birds to retain their metabolically generated heat. An efficient respiratory system and a circulatory system with a four-chambered heart keep tissues well supplied with oxygen and nutrients, supporting a high rate of heat and reduce the density of the body metabolism. The lungs have tiny tubes leading to and from elastic air sacs that help dissipate. For safe flight, senses, especially vision, must be acute. Birds have excellent eyes, perhaps the best of all the vertebrates. The visual areas of the brains are well developed, as are the motor areas: flight also requires excellent coordination. With brains proportionately larger than those of reptiles and amphibians, birds generally display very complex behavior. Avian behavior is particularly intricate during breeding season, when birds engage in elaborate rituals of courtship. Because eggs are shelled when laid, fertilization must be internal. Copulation involves contact between the mates' vents, the openings to their cloacas. After eggs are laid, the avian embryo must be kept warm through brooding by the mother, father, or both, depending on the species. A bird's most obvious adaptation for flight is its wings. Bird wings are airfoils that illustrate the same principles of aerodynamics as the wings of an airplane. Providing power for flight, birds flap their wings by contractions of large pectoral(breast)muscles anchored to a keel on the sternum(breast-bone). Some birds, such as eagles and hawks, have wings adapted for soaring on air currents and flap their wings only occasionally, other birds, including hummingbirds, must flap continuously to stay aloft. In either case, it is the shape and arrangement of the feathers that form the wings into an airfoil. The fastest birds are the appropriately named swifts, which can fly 170 km/hr. In being both extremely light and strong, feathers are among the most remarkable of vertebrate adaptations. Feathers are made of keratin, the same protein that forms our hair and fingernails and the scales of reptiles. Feathers may have functioned first as insulation during the evolution of endotherm, only later being so-opted as flight equipment. Analyses of fossilized skeletons support the hypothesis that the closest reptilian relatives of birds were the theropods, a group of relatively small, bipedal carnivorous dinosaurs. Most researchers agree that the ancestor of birds was a feathered theropod. However, some scientists place the origin of birds much earlier, from an ancestor common to both birds and dinosaur. The intense current interest in the origin of birds will undoubtedly bring us closer to understanding how these masters of the sky evolved from non-flying reptiles

单选题The doctor said that it would take a month for her fractured wrist to ______.

单选题Just imagine the shock of the Prime Minister when three of his senior cabinet colleagues______ and resigned in protest on Friday night. A. revolved B revived C. resolved D. revolted

单选题The ______ of gifted children into accelerated classes will start next week according to their academic performance.

单选题Since there was no capital punishment in that country, the murderer was ______ to life imprisonment. A. judged B. confessed C, verified D. condemned

单选题He had scarcely left the railway station ______ it started to rain. A. than B. then C. when D. since

单选题The next time the men were taken up onto the deck, Kunta made a point of looking at the man behind him in line, the one who lay beside him to the left when they were below. He was a Serer tribesman much older than Kunta, and his body, front and back, was creased with whip cuts, some of them so deep and festering that Kunta, felt badly for having wished sometimes that be might strike the man in the darkness for moaning so steadily in his pain. Staring back at Kunta, the Serer's dark eyes were full of fury and defiance. A whip lashed out even as they stood looking at each other--this time at Kunta, spurring him to move ahead. Trying to roll away, Kunta was kicked heavily in his ribs. But somehow he and the gasping Wolof managed to stagger back up among the other men from their shelf who were shambling toward their dousing with bucked of seawater. A moment later, the stinging saltiness of it was burning in Kunta's wounds, and his screams joined those of others over the sound of the drum and the wheezing thing that had again begun marking time for the chained men to jump and dance for the toubob. Kunta and the Wolof were so weak from their new beating that twice they stumbled, but whip blows and kicks sent them hopping clumsily up and down in their chains. So great was his fury that Kunta was barely aware of the women singing "Toubob fa!" And when he had finally been chained back down in his place in the dark hold, his heart throbbed with a lust to murder toubob. Every few days the eight naked toubob would again Come into the stinking darkness and scrape their tubs full of the excrement that had accumulated on the shelves where the chained men lay. Kunta would lie still with his eyes staring balefully in hatred, following the bobbing orange lights, listening to the toubob cursing and sometimes slipping and tailing into the slickness underfoot--so plentiful now, because of the increasing looseness of the men's bowels, that the filth had begun to drop off the edges of the shelves down into the aisleway. The last time they were on deck, Kunta had noticed a man limping on a badly infected leg. This time the man was kept up on deck when the rest were taken back below. A few days later, the women told the other prisoners in their singing that the man's leg had been cut off and that one of the women had been brought to tend him, but that the man had died that night and been thrown over the side. Starting then, when the toubob came to clean the shelves, they also dropped re& hot pieces of metal into pails of strong vinegar. The clouds of acrid steam left the hold smelling better, but soon it would again be overwhelmed by the choking stink. It was a smell that Kunta felt would never leave his lungs and skin. The steady murmuring that went on in the hold whenever the toubob were gone kept growing in volume and intensity as the men began to communicate better and better with one another. Words not understood were whispered from mouth to ear along the shelves until someone who knew more than one tongue would send back their meanings. In the process, all of the men along each shelf learned new words in tongues they had not spoken before. Sometimes men jerked upward, bumping their heads, in the double excitement of communicating with each other and the fact that it was being done without the toubob's knowledge. Muttering among themselves for hours, the men developed a deepening sense of intrigue and of brotherhood. Though they were of different villages and tribes, the feeling grew that they were not from different peoples or places.

单选题Through the discussion they gained an extraordinary insight into the complexity of women's emotions. A. cleverness of B. knowledge of C. prediction of D. perception of