单选题In no country ______ Britain, it has been said, can one experience four seasons in the course ora single day.

单选题If you grow up in ______ large family ,you are more likely to develop ______ ability to get on well with ______ others. A. /, an, the B. a, the, / C. the, an, the D. a, the, the

单选题The World Bank is taking steps to ______ its lending to reducing poverty in the Third World Countries.

单选题So far there is no proof ( ) people from other planets do exist.

单选题Saul's brother left the matter entirely up to ______ and ______.

单选题What he is ______ is neither money nor fame, but the satisfaction of seeing his students grow up as builders of socialism.

单选题The three boys were given work according to their ______ abilities.

单选题 Scientists have invented a 3D scan technology to read the otherwise illegible wood-carved stone, a method that may apply to other areas such as medicine.

单选题His goal is not to become a sportsman______a champion in a certain field.

单选题A: How did you do with your essay for Professor Smith Scott? B: ______.

单选题Despite increased airport security since September 11th, 2001, the technology to scan both passengers and baggage for weapons and bombs remains largely unchanged. Travellers walk through metal detectors and carry-on bags pass through x-ray machines that superimpose colour-coded highlights, but do little else. Checked-in luggage is screened by "computed tomography", which peers inside a suitcase rather like a CAT scan of a brain. These systems can alert an operator to something suspicious, but they cannot tell what it is. More sophisticated screening technologies are emerging, albeit slowly. There are three main approaches: enhanced x-rays to spot hidden objects, sensor technology to sniff dangerous chemicals, and radio frequencies that can identify liquids and solids. A number of manufacturers are using "reflective" or "backscatter" x-rays that can be calibrated to see objects through clothing. They can spot things that a metal detector may not, such as a ceramic knife or plastic explosives. But some people think they can reveal too much. In America, civil-liberties groups have stalled the introduction of such equipment, arguing that it is too intrusive. To protect travellers 'modesty, filters have been created to blur genital areas. Machines that can detect minute traces of explosive are also being tested. Passengers walk through a machine that blows a burst of air, intended to dislodge molecules of substances on a person's body and clothes. The air is sucked into a filter, which instantaneously analyses it to see whether it includes any suspect substances. The process can work for baggage as well. It is a vast improvement on today's method, whereby carry-on items are occasionally swabbed and screened for traces of explosives. Because this is a manual operation, only a small share of bags are examined this way. The most radical of the new approaches uses "quadrupole resonance technology". This involves bombarding an object with radio waves. By reading the returning signals, the machines can identify the molecular structure of the materials it contains. Since every compound—solid, liquid or gas—creates a unique frequency, it can be read like a fingerprint. The system can be used to look for drugs as well as explosives. For these technologies to make the jump from development labs and small trials to full deployment at airports they must be available at a price that airports are prepared to pay. They must also be easy to use, take up little space and provide quick results, says Chris Yates, a security expert with Jane's Airport Review. Norman Shanks, an airport security expert, says adding the new technologies costs around $100,000 per machine; he expects the systems to be rolled out commercially over the next 12 months. They might close off one route to destroying an airliner, but a cruel certainty is that terrorists will try to find others.

单选题Mr. Smith asked his secretary to ______ a new paragraph in the annual report she was typing.

单选题Panic swept through the swimmers as they caught sight of a huge shark approaching menacingly.

单选题 Aided by the recent ability to analyze samples of air trapped in glaciers, scientists now have a clearer idea of the relationship between atmospheric composition and global temperature changing over the past 160,000 years. In particular, determination of atmospheric composition during periods of glacial expansion and retreat (cooling and warming) is possible using data from the 2,000 meter Vostok ice core drilled in Antarctica. The technique involved is similar to that used in analyzing cores of marine sediments, where the ratio of the two common isotopes of oxygen, 180 and 160, accurately reflects past temperature changes. Isotopic analysis of oxygen in the Vostok core suggests mean global temperature fluctuations of up to 10 degrees centigrade over the past 160,000 years. Data from the Vostok core also indicate that the amount of carbon dioxide has fluctuated with temperature over the same period: the higher the temperature, the higher the concentration of carbon dioxide and the lower the temperature, the lower the concentration. Although change in carbon dioxide content closely follows change in temperature during periods of deglaciation, it apparently lags behind temperature during periods of cooling. The correlation of carbon dioxide with temperature, of course, does not establish whether changes in atmospheric composition causing the warming and cooling trends or were caused by them. The correlation between carbon dioxide and temperature throughout the Vostok record is consistent and predictable. The absolute temperature changes, however, are from 5 to 14 times greater than would be expected on the basis of carbon dioxide's own ability to absorb infrared radiation, or radiant heat. This reaction suggests that, quite aside from changes in heat-trapping gases, commonly known as greenhouse gases, certain positive feedbacks are also amplifying the temperature change. Such feedbacks might involve ice on land and sea, clouds, or water vapor, which also absorb radiant heat. Other data from the Vostok core show that methane gas also correlates closely with temperature and carbon dioxide. The methane concentration nearly doubled, for example, between the peak of the penultimate glacial period and the following interglacial period. Within the present interglacial period it has more than doubled in just the past 300 years and is rising rapidly. Although the concentration of atmospheric methane is more than two orders of magnitude lower than that of carbon dioxide, it cannot be ignored: the radiative properties of methane make it 20 times more effective, molecule for molecule, than carbon dioxide in absorbing radiant heat. On the basis of a simulation model that climatological researchers have developed, methane appears to have been about 25 percent as important as carbon dioxide in the warming that took place during the most recent glacial retreat 8,000 to 10,000 years ago.

单选题Carbon is a(n)______ while carbon dioxide is a compound.

单选题There is nothing more possible than a new hip or knee that can put the spring back in your step. Patients receiving joint implants （移植） often are able to resume many of the physical activities they lo

单选题A: That was a delicious meal, Mrs. Barr. Thank you very much.B: ______

单选题All tickets________from this site are supplied by AAA Tickets Ltd, an official ticketing company.

单选题 Domestic Service Robots A. When Takanori Shibata began working on robots in the early 1990s, he had something practical in mind, perhaps to help the elderly with their daily chores. But he soon realized that robots were not really able to do anything useful, so he decided to make a robot that did not even try—but that could nevertheless deliver real benefits. B. The result of his labors, Paro, has been in development since 1998. It is 57cm long and looks like a baby seal. Thanks to an array of sub-skin sensors, it responds amiably to stroking; and though it cannot walk, it can turn its head at the sound of a human voice and tell one voice from another. It is a comforting and gentle presence in your arms, on your lap or on a table top, where it gives the impression of following a conversation. The best thing about it is that it seems to be helping in the care of people with dementia (痴呆) and other health problems. C. You could see Paro as a very well-designed $5,000 pet that will never turn on the person holding it, and will never be hurt if its master flies into a rage. It is as happy on one lap as the next, needs no house-training, can be easily washed and will not die. This makes it much more practical for a nursing home or hospital than a live pet. It is used in such homes in Japan, in parts of Europe and in America. D. Paro can also act as a source of reassurance and calm. People with Alzheimer's often suffer from 'sun-downing'—a distressed urge to wander that comes on towards the end of the afternoon. Mr. Shibata has found that a seal in the arms tends to reduce such wandering, which means fewer falls. Experience in Italy, Denmark and America indicates that care homes equipped with Paro need less medication for their residents. Larger trials now under way in Australia should establish whether this and other benefits can be provided simply by a soft toy, or whether Paro's ability to interact with the world makes a clinical difference. E. If Paro proves to be more useful than a plush (毛绒) animal, there is a huge market for it. Akifumi Kitashima, who works on Japan's robotics strategy at the Ministry for the Economy, Trade and Industry, points out that in 2025 Japan will have 10.7 million more elderly people than it did in 2005. Though Japan is ageing particularly quickly, a lot of the rest of the world is on a. similar course. F. Looking after old people in homes might become easier with robots, be they mood enhancers like Paro or something more practical that can help careworkers lift and reposition their charges (受照料者). Yoshiyuki Sankai, perhaps Japan's best-known robotics entrepreneur, has set up a company called Cyberdyne to make wearable systems that help people walk and lift things by adding artificial strength to their limbs. G. Robots may also make it possible for old people to stay independent in their own homes for longer. Mr. Angle says this is iRobot's 'long-term guiding star', towards which the Roomba—a cleaning robot—is a small step. Mr. Gupta at the National Science Foundation thinks that general-purpose home-help robots would be a big advance which could be achieved in a couple of decades. Another robotics expert Mr. Ng points out that if you get a graduate student to teleoperate (远程操控) a PR2 robot, it can already do almost everything a home-help robot might be required to do, so all that is needed is better software and more processing power, both of which are becoming ever more easily available. H. Cloud robotics can probably provide much of the required software. Mr. Pratt says that if there were dramatic performance improvements in the finals of the DARPA Robotics Challenge, he would expect them to come from the cloud. I. But specific robot hardware will need upgrading, too. No robot hand yet comes close to the utility of the human hand. Tasks that require feedback in terms of force and fit—like putting a plug into a socket—remain particularly hard for robots, and there are a lot of such tasks around a house. General technological progress will not help; the only way to find a solution to this sort of problem is to work specifically on it. J. Even more important will be interfaces (界面) to tell the robots what to do. Take-me-by-the-wrist Baxter, stroke-me Paro and the film-enabling mechanical arms of Bot Dolly all show that interfaces can matter just as much as any other technological advance. Tobias Kinnebrew, of Bot Dolly, thinks that new interfaces could open up markets and applications of robotics in all sorts of fields, and might do so surprisingly quickly. K. Voice would be an obvious choice, but it has its drawbacks: the user will think a robot with a voice is smart. An interface that allows the robot to be dumb and the user not to care might be preferable. Indeed, small errors or needing help with something can be endearing. People do not resent Paro's need to be stroked; it is one of the things they like about it. CoBot's need for help with the lifts at Carnegie Mellon makes people warm to it, though being troubled for help by random robots in offices and shopping malls would probably not work so well. But if the interface is properly designed, teaching a home-help robot to do the job better might make it more welcome. L. It may also be a good idea to let the robots turn for help to people other than those they are working for. As Mr. Goldberg at Berkeley points out, the cloud does not just contain computers; it provides access to a lot of humans, too. One of the things that make Aethon's Tugs a success in hospitals is that the company's headquarters has a staffed help desk which deals with queries from robots. If one gets stuck or lost, a remote operator can look through its eyes, check its logs and sort things out before the hospital even becomes aware that anything is wrong. If similar support could be provided for robot home helps, the occasional mistake might not matter. M. If the robot can call on a help desk, it can communicate with other people too, perhaps providing a way for friends and relatives to stay in touch. Some home-automation products already allow a degree of monitoring, notes Oz Chambers of Carnegie Mellon, but what they offer leaves much to be desired. It makes the adult offspring feel greater responsibility—which they often cannot exercise—rather than giving them reassurance. The elderly, for their part, can feel snooped (窥探) upon. A robot with a defined presence in the house might make a better intermediary. N. What matters, as iRobot and other practically minded companies have learned, is not so much having robots but having a business model that does a job, be it washing the dishes, checking that medication is being taken or providing telepresence (远程监控). Producing something reliable and likeable that can be sold in large numbers and does not get its makers sued may prove a lot more difficult than simply developing the required robotic skills, but not impossible. O. To be sure, robots will not spread as quickly as mobile phones have done. Over a decade they may not achieve much. Over a century, though, they could turn everyday life upside down.