单选题What does Moravec think of these future robots?

单选题The economy continued to exhibit signs of decline in September.

单选题 Green Roof Research The concept of green roofs is basically about growing plants on roofs, thus helping to replace the green footprint that had been destroyed due to the construction of the building. Green roofs are the most prevalent (流行) in Germany, which is widely regarded as the leader in green roof research. The green roofs that are used these days can be classified as "extensive" and "intensive" systems. Extensive green roofs use mosses, grasses and herbs, which are tolerant to droughts. These plants do not need much maintenance, can be grown in a layer of substrate (土层) that can be as shallow as 1.5 inches, and generally are inaccessible to the public. In contrast, a wide range of species of plants are grown on intensive green roofs, such as shrubs (灌木) and even trees, which require deeper substrate layers, and are usually grown on flat roofs. They need intensive maintenance, and are usually areas that resemble parks which are accessible to people. There are several benefits of adopting green roof technologies. Apart from the obvious psychological and aesthetic (审美学的) benefits of garden—like environments surrounding you, some of the common economic and ecological benefits are: a reduction in the consumption of energy; air and water purification; recovering green spaces; and the mitigation (缓解) of the heat island effect in urban areas. The green roof research that is currently ongoing is focused on evaluating the species of plants that are suitable to be grown on roofs, the methods of propagation (繁殖) as well as establishment, nutrient (养料) and water requirement, substrates, and the quantity and quality of water runoff. The evaluation criteria of plant species are: at what rate they can be established their capacity to withstand invasive weeds; tolerance of cold and heat; tolerance of drought conditions; capacity of persistence and survival. A number of experiments are being conducted on roof platform simulations at various research centers. These sites are generally outfitted with equipment, which are used to measure temperatures at different depths of the growing substrates, and the rate and volume of the runoff of stormwaters from each of the platforms. Green roof technology is representative of a completely new market for landscape contractors, and all roofs that currently exist and the future ones to be constructed are the potential market—a market that is too huge to be overlooked.

单选题We have got to abide by the rules.

单选题Nowadays nearly everyone has suffered from a bad attack of forgetfulness when a password is needed. The company computer, the home computer, banking and ATM machines, Websites, car and home security systems. The list goes on. It does not take long to accumulate a dozen or more passwords. Scribbling them down on slips of paper or simply using the same password for anything and everything is how most people cope with the overload. The negative aspect of this is that either way makes it easier for hackers to invade computer privacy. Using the same password for everything may result inA. the user's forgetfulness.B. the user's overload.C. the loss of banking accounts.D. the theft of privacy.

单选题第一篇 Pool Watch Swimmers can drown in busy swimming pools when lifeguards fail to notice that they are in trouble. The Royal Society for the Prevention of Accidents says that on average 15 people drown in British pools each year, but many more suffer major injury after getting into difficulties. Now a French company has developed an artificial intelligence system called Poseidon that sounds the alarm when it sees someone in danger of drowning. When a swimmer sinks towards the bottom of the pool, the new system sends an alarm signal to a poolside monitoring station and a lifeguard"s pager. In trials at a pool in Ancenis, near Nantes, it saved a life within just a few months, says Alistair McQuade, a spokesman for its maker, Poseidon Technologies. Poseidon keeps watch through a network of underwater and overheard video cameras. AI software analyses the images to work out swimmers trajectories. To do this reliably, it has to tell the difference between a swimmer and the shadow of someone being cast onto the bottom or side of the pool. "The underwater environment is a very dynamic one, with many shadows and reflections dancing around." says McQuade. The software does this by "projecting" a shape in its field of view onto an image of the far wall of the pool. It does the same with an image from another camera viewing the shape from a different angle. If the two projections are in the same position, the shape is identified as a shadow and is ignored. But if they are different, the shape is a swimmer and so the system follows its trajectory. To pick out potential drowning victims, anyone in the water who starts to descend slowly is added to the software"s "pre-alert" list, says McQuade. Swimmers who then stay immobile on the pool bottom for 5 seconds or more are considered in danger of drowning. Poseidon double-checks that the image really is of a swimmer, not a shadow, by seeing whether it obscures the pool"s floor texture when viewed from overhead. If so, it alerts the lifeguard, showing the swimmer"s location on a poolside screen. The first full-scale Poseidon system will be officially opened next week at a pool in High Wycombe, Buckinghamshire. One man who is impressed with the idea is Travor Baylis, inventor of the clockwork radio. Baylis runs a company that installs swimming pools, and he was once an underwater escapologist with a circus. "I say full marks to them if this works and can save lives," he says. But he adds that any local authority spending ￡30,000-plus on a Poseidon system ought to be investing similar amounts in teaching children to swim.

单选题In some cases managers have to learn how to write programs so as to work out computerized information systems that suit their own companies best.

单选题The Need to Remember Some people say they have no memory at all: "I just can't remember a thing!" But of course we all have a memory. Our memory tells us who we are. Our memory helps us to make use in the present of what we have learnt in the past. In fact we have different types of memory, For example, our visual memory helps us recall facts and places. Some people have such a strong visual memory, they can remember exactly what they have seen, for example, pages of a book, as a complete picture. Our verbal (言语的) memory helps us remember words and figures we may have heard but not seen or written: items of a shopping list, a chemical formula, dates, or a recipe. With our emotional (情感的) memory, we recall situations or places where we had strong feelings, perhaps of happiness or unhappiness. We also have special memories for smell, taste, touch and sound, and for performing physical movements. We have two ways of storing any of these memories. Our short-term memory stores items for up to thirty seconds - enough to remember a telephone number while we dial. Our long-term memory, on the other hand, may store items for a lifetime. Older people in fact have a much better long-term memory than short-term. They may forget what they have done only a few hours ago, but have the clearest remembrance (记忆) of when they were very young. Psychologists tell us that we only remember a few facts about our past, and that we invent the rest. It is as though we remember only the outline of a story. We then make up the details. We often do this in the way we want to remember them, usually so that we appear as the heroes of our own past - or maybe victims needing sympathy (同情).

单选题The most widely seen sculptural work clone by Augusta Savage was probably "Lift Every Voice and Sing" , shown at the 1939-1940 New York world's fair.

单选题Before the supper, my morn asked me to {{U}}lay{{/U}} the table.

单选题Japan made a proposal to Korea for increasing trade between two countries. A. preparation B. exception C. suggestion D. companion

单选题The conclusion can be {{U}}deduced{{/U}} from the premises.

单选题She stared at his son and shaked with anger.

单选题She was one of the Uleading/U writers of her day.

单选题His idea to solve the problem is really original .

单选题Her faith Uupheld/U her in times of sadness.

单选题Experts Call for Local and Regional Control of Sites for Radioactive Waste The withdrawal of Nevada's Yucca Mountain as a potential nuclear waste repository has reopened the debate over how and where to dispose of spent nuclear fuel and high-level nuclear waste. In an article in the July 10 issue of Science, University of Michigan geologist Rodney Ewing and Princeton University nuclear physicist Frank yon Hippel argue that, although federal agencies should set standards and issue licenses for the approval of nuclear facilities, local communities and states should have the final approval on the siting of these facilities. The authors propose the development of multiple sites that would service the regions where nuclear reactors are located. "The main goal..., should be to provide the Unied States with multiple alternatives and substantial public involvement in an open siting and design process that requires acceptance by host communities and states," the authors write. Ewing and yon Hippel also analyze the reasons why Yucca Mountain, selected by Congress in 1987 as the only site to be investigated for long-term nuclear waste disposal, finally was shelved after more than three decades of often controversial debate. The reasons include the site's geological problems, management problems, important changes in the Environmental Protection Agency's standard, unreliable funding and the failure to involve local communities in the decision-making process. Going forward, efforts should be directed at locating storage facilities in the nation's northeastern, southeastern, mid-western and western regions, and states within a given region should be responsible for developing solutions that suit their particular circumstances. Transportation of nuclear waste over long distances, which was a concern with the Yucca Mountain site, would be less of a problem because temporary storage or geological disposal sites could be located closer to reactors. "This regional approach would be similar to the current approach in Europe, where spent nuclear fuel and high-level nuclear waste from about 150 reactors and reprocessing plants is to be moved to a number of geological repositories in a variety of rock types," said Rodney Ewing, who has written extensively about the impact of nuclear waste management on the environment and who has analyzed safety assessment criteria for the controversial Yucca Mountain nuclear waste repository.

单选题Water The second most important constituent(构成成份)of the biosphere(生物圈)is liquid water. This can only exist in a very narrow range of temperatures, since water freezes at 0℃ and boils at 100℃. Life as we know it would only be possible on the surface of a planet which had temperatures somewhere within this narrow range. The earth's supply of water probably remains fairly constant in quantity. The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers. Most of it is in the form of the salt water of the oceans -- about 97 percent. The rest is fresh,but three-quarters of this is in the form of ice at the Poles and on mountains, and cannot be used by living systems until melted. Of the remaining fraction, which is somewhat less than one percent of the whole,there is 10～20 times as much stored underground water as there is actually on the surface. There is also a tiny, but extremely important fraction of the water supply which is present as waer vapour in the atmosphere. Water vapour in the atmosphere is the channel through which the whole water circulation(循环)of the biosphere has to pass. Water evaporated(蒸发)from the surface of the oceans,from lakes and rivers and from moist(潮湿的)earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected,a more intensive evaporation per unit area over the sea and oceans than over the land, but there is more rainfall over the land than over the oceans and the balance is restored by the runoff from the land in the form of rivers.

单选题Retirement Brings Most a Big Health Boost The self-reported health of the newly retired improves so much that most feel eight years younger, a new European study suggests. This happy news was true of almost everyone except a small minority—only 2 percent who had experienced "ideal" conditions in their working life, anyway. "The results really say three things: that work puts an extra burden on the health of older workers, that the effects of this extra burden are largely relieved by retirement and, finally, that both the extra burden and the relief are larger when working conditions are poor," said Hugo Westerlund, lead author of a study published online Nov. 9 in the Lancet . "This indicates that there is a need to provide opportunities for older workers to decrease the demands in their work out of concern for their health and well-being." But of course, added Westerlund, who is head of epidemiology at the Stress Research Institute at Stockholm University in Sweden, "not all older workers suffer from poor perceived health. Many are indeed remarkably healthy and fit for work. But sooner or later, everyone has to slow down because of old age catching up." Last week, the same group of researchers reported that workers slept better after retirement than before. "Sleep improves at retirement, which suggests that sleeping could be a mediator between work and perception of poor health," Westerlund said. This study looked at what the same 15,000 French workers, most of them men, had to say about their own health up to seven years pre-retirement and up to seven years post-retirement. As participants got closer to retirement age, their perception of their own health declined, but went up again during the first year of retirement. Those who reported are being in poorer health declined from 19.2 percent in the year prior to retirement to 14.3 percent by the end of the first year after retiring. According to the researchers, that means post-retirement levels of poor health fell to levels last seen eight years previously. The changes were seen in both men and women, across different occupations, and last-edthrough the first seven years of not punching the clock. Workers who felt worse before retirement and had lower working conditions reported greater improvements as soon as they retired, the team found.

单选题He has trouble understanding that other people judge him by his social skills and conduct .