单选题 Over the past decade, the environmental movement has exploded onto the mind of mainstream consumers, a fact not lost on marketers and advertisers. Green advertising started in the mid-1980s when issues of the environment muscled their way to the forefront of marketing. Advertisers saw the consumer desire for environmentally safe products and tried to meet the demand as quickly as possible. Not surprisingly, this first wave suffered from rough and poorly conceived marketing efforts. Many advertisers embraced a genuine concern for the environment. But consumers realized that some companies made false claims and exploited the movement, using such nebulous (模糊的) terms as 'environmentally friendly' and 'green' Consumers grew wary of environmental appeals, and advertisers reacted by reducing its emphasis. To avoid future trouble, many companies waited for state and federal governments to define terms and provide legal guidelines, which paved the road to a second wave. In 1992 the Federal Trade Commission established guidelines for green marketing, followed shortly by state governments. California passed particularly strict laws, setting definitions for terms like 'ozone friendly', 'biodegradable', and 'recycled'. According to the state's court, 'California seeks to guard against potentially specious; claims or ecological puffery (吹捧) about products with minimal environmental attributes.' Texas, Massachusetts, Minnesota, Tennessee, Connecticut, and Washington soon followed the Golden State's lead. The rigid regulations have left a number of advertisers confused and frustrated, although some feel that environmental claims have already peaked and are on their way out. Some believe that we've now entered green advertising's third wave, where environmental concern is now part of the mainstream.

单选题 Directions: For this part, you are allowed 80 minutes to write an essay. Suppose there are two views on the key to becoming a talented person: One is personal abilities and the other opportunities. You are to make a choice between the two. Write an essay to explain the reasons for your choice. You should write at least 120 words but no more than 180 words.

单选题 Desert Formation A. The deserts, which already occupy approximately a fourth of the Earth's land surface, have in recent decades been increasing at an alarming pace. The expansion of desert-like conditions into areas where they did not previously exist is called desertification. It has been estimated that an additional one-fourth of the Earth's land surface is threatened by this process. B. Desertification is accomplished primarily through the loss of stabilizing natural vegetation and the subsequent accelerated erosion of the soil by wind and water. In some cases the loose soil is blown completely away, leaving a stony surface. In other cases, the finer particles may be removed, while the sand-sized particles are accumulated to form mobile hills or ridges of sand. C. Even in the areas that retain a soil cover, the reduction of vegetation typically results in the loss of the soil's ability to absorb substantial quantities of water. The impact of raindrops on the loose soil tends to transfer fine clay particles into the tiniest soil spaces, sealing them and producing a surface that allows very little water penetration. Water absorption is greatly reduced; consequently runoff is increased, resulting in accelerated erosion rates. The gradual drying of the soil caused by its diminished ability to absorb water results in the further loss of vegetation, so that a cycle of progressive surface deterioration is established. D. In some regions, the increase in desert areas is occurring largely as the result of a trend toward drier climatic conditions. Continued gradual global warming has produced an increase in aridity for some areas over the past few thousand years. The process may be accelerated in subsequent decades if global warming resulting from air pollution seriously increases. E. There is little doubt, however, that desertification in most areas results primarily from human activities rather than natural processes. The semiarid lands bordering the deserts exist in a delicate ecological balance and are limited in their potential to adjust to increased environmental pressures. Expanding populations are subjecting the land to increasing pressures to provide them with food and fuel. In wet periods, the land may be able to respond to these stresses. During the dry periods that are common phenomena along the desert margins, though, the pressure on the land is often far in excess of its diminished capacity, and desertification results. F. Four specific activities have been identified as major contributors to the desertification processes: over-cultivation, over-grazing, firewood gathering, and over-irrigation. The cultivation of crops has expanded into progressively drier regions as population densities have grown. These regions are especially likely to have periods of severe dryness, so that crop failures are common. Since the raising of most crops necessitates the prior removal of the natural vegetation, crop failures leave extensive tracts of land devoid of a plant cover and susceptible to wind and water erosion. G. The raising of livestock is a major economic activity in semiarid lands, where grasses are generally the dominant type of natural vegetation. The consequences of an excessive number of livestock grazing in an area are the reduction of the vegetation cover and the trampling and pulverization of the soil. This is usually followed by the drying of the soil and accelerated erosion. Firewood is the chief fuel used for cooking and heating in many countries. The increased pressures of expanding populations have led to the removal of woody plants so that many cities and towns are surrounded by large areas completely lacking in trees and shrubs. The increasing use of dried animal waste as a substitute fuel has also hurt the soil because this valuable soil conditioner and source of plant nutrients is no longer being returned to the land. H. The final major human cause of desertification is soil salinization resulting from over-irrigation. Excess water from irrigation sinks down into the water table. If no drainage system exists, the water table rises, bringing dissolved salts to the surface. The water evaporates and the salts are left behind, creating a white crustal layer that prevents air and water from reaching the underlying soil. The extreme seriousness of desertification results from the vast areas of land and the tremendous numbers of people affected, as well as from the great difficulty of reversing or even slowing the process. Once the soil has been removed by erosion, only the passage of centuries or millennia will enable new soil to form. In areas where considerable soil still remains, though, a rigorously enforced program of land protection and cover-crop planting may make it possible to reverse the present deterioration of the surface. I. In geography, an oasis is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source. Oases also provide habitat for animals and even humans if the area is big enough. The location of oases has been of critical importance for trade and transportation routes in desert areas. Caravans must travel via oases so that supplies of water and food can be replenished. Thus, political or military control of an oasis has in many eases meant control of trade on a particular route. For example, the oases of Awjila, Ghadames and Kufra, situated in modem-day Libya, have at various times been vital to both North-South and East-West trade in the Sahara. Oases are formed from underground rivers or aquifers such as an artesian aquifer, where water can reach the surface naturally by pressure or by man made wells. Occasional brief thunderstorms provide subterranean water to sustain natural oases, such as the Tuat. Substrata of impermeable rock and stone can trap water and retain it in pockets, or on long faulting subsurface ridges or volcanic dikes water can collect and percolate to the surface. Any incidence of water is then used by migrating birds who also pass seeds with their droppings which will grow at the water's edge forming an oasis.

单选题 Babies cry to call attention to their immediate needs: food, or rest, or a diaper change or cuddles. But without intending to, crying babies might also provide insight into a defining trait that will develop later in life. As Matt Stevens of the New York Times reports, a new study has found that the pitch of a baby's cry could predict what he or she will sound like as an adult. Researchers in the U.K. and France wondered if vocal pitch might be determined even earlier than age seven—during infancy, perhaps, or even in the womb (子宫). To find out, the team recorded the cries of 15 French babies—six girls and nine boys, from two to five months old. Researchers then compared those recordings to recordings of the same children at age four or five. The team found that the pitch of babies' cries was a 'substantial predictor' of vocal pitch at four or five years of age. 'Differences in voice pitch,' the researchers conclude, 'may—at least partly—arise very early in life.' The authors of the study suggest that these differences might develop in the womb, when fetuses are exposed to varying levels of hormones. As Carl Engelking of Discover reports, the team also analyzed the children's 2D:4D digit ratio, or the ratio between the lengths of the index finger and the ring finger. Studies have suggested that this ratio can reveal how much testosterone (睾丸激素) a person was exposed to in the womb. Researchers found that 2D:4D digit ratio in the right hand correlated positively with differences in vocal frequency in both baby cries and children's speech (this is consistent with other studies showing that 2D:4D ratios are expressed more strongly in the right hand). In other words, as a statement announcing the new research explains, 'if the index finger on the right hand is longer than the ring finger, a baby will be likely to grow up to have a high-pitched voice. Conversely, if it is shorter, they will be more likely to have a lower-pitched voice.'

单选题The popular notion that older people need less sleep than younger adults is a myth, scientists said yesterday. While elderly people 25 to sleep for fewer hours than they did when they were younger, this has a(n) 26 effect on their brain's performance and they would benefit from getting more, according to research. Scan Drummond, a psychiatrist (生理医生) at the University of California, San Diego, said that older people are more likely to suffer from broken sleep, while younger people are better at sleeping 27 straight through the night. More sleep in old age, however, is 28 with better health, and most older people would feel better and more 29 if they slept for longer periods, he said. 'The ability to sleep in one chunk (整块时间) overnight goes down as we age but the amount of sleep we need to 30 well does not change, ' Dr Drummond told the American Association for the Advancement of Science conference in San Diego. 'It's 31 a myth that older people need less sleep. The more healthy an older adult is, the more they sleep like they did when they were 32 . Our data suggests that older adults would benefit from 33 to get as much sleep as they did in their 30s. That's 34 from person to person, but the amount of sleep we had at 35 is probably the same amount as we need at 75.' A. alert B. associated C. attracting D. cling E. continuing F. definitely G. different H. efficiently I. formally J. function K. mixed L. negative M. sufficient N. tend O. younger

单选题 The number of postgraduate students travelling from non-EU countries to study at UK universities has fallen for the first time in 16 years, fuelling fears that the government's immigration crackdown is discouraging thousands of the brightest students from continuing their studies in Britain. JoBeall, British Council director of education and society, said the fall would cause alarm among UK vice-chancellors (大学行政主管理). 'The sector was expecting a decline in growth, but the actual reduction in postgraduate numbers is of real concern as international students make up the majority of numbers in many postgraduate courses and research teams in science, technology, engineering and mathematics.' 'Attracting the brightest and most ambitious postgraduate and research students is critical if the UK is to maintain its quality reputation for research,' Beall said. Universities get a third of their tuition (学费) fee revenue from non-EU students. There is growing fear among vice-chancellors that this revenue-as well as the cultural, academic and economic benefit international students bring-is being put at risk. Tim Westlake, director for the student experience at Manchester University, said students whose families relied on them working in the UK after their studies to gain experience and repay the fees were starting to look elsewhere. Last month the home secretary, Theresa May, announced that embassy staff would interview more than 100 000 applicants in an attempt to prevent bogus (假冒的) ones entering the country. She also said immigrants were responsible for pushing up UK house prices. The comments followed the introduction of new limitations on students' right to work during and after their studies. Beall said: 'Government statistics for the first time provide real evidence that the changes to UK visa regulations may have discouraged many students from applying to the UK. and in particular postgraduate students who are so important to the UK's research output. The UK enjoys an excellent reputation around the world for the high quality of our education system, so the government needs to ensure that institutions have all the support they need to attract international students who make a tremendous academic, cultural and economic contribution to the UK.'

单选题 Google researchers have used artificial intelligence (AI) to teach robots how to move like real animals (in this case, dogs). They describe their experiment in a blog released this week. 'First, we describe how robots can learn to move like a real animal by imitating their motions, producing fast and fluent movements like running slowly and hopping. Then, we discuss a system for automating the training of moving skills in the real world, which allows robots to learn to walk on their own, with minimal human assistance,' shared in the blog Xue Bin (Jason) Peng, Student Researcher and Sehoon Ha, Research Scientist, Robotics at Google. They achieved this impressive feat by using something called reinforcement learning (RL). They began by taking a reference video recorded from an animal and using RL to get the robot to imitate an animal's movement. 'By providing the system with different reference motions, we are able to train an animal-shaped robot to perform a diverse set of agile behaviors, ranging from fast walking to dynamic hops and turns. The policies are trained primarily in simulation(模拟，模仿), and then transferred to the real world using a space adaptation technique that can efficiently adapt a policy using only a few minutes of data from the real robot,' wrote the researchers in their blog. However, it is a well-known fact that simulators provide a poor approximation of the real world, meaning that simulations don't perform well in reality. This is where the researchers decided to use a sample-efficient space adaptation technique. They did so by introducing an element of randomness to the physical parameters(参数) used in the simulation by varying physical quantities, such as the robot's mass and friction. This resulted in a machine learning model that could account for all kinds of small changes and the complications they create. The end result is a robot that moves like a real dog. This kind of work is crucial as it can open opportunities to use robots to do sophisticated tasks in the real world.