单选题Thick clouds obscured the stars from view. A. darkened B. held C. blackened D. prevent

单选题 A Trip Every year New Zealanders living in London can be seen loading up Kombi vans and heading off to experience the "classic European holiday". The trip usually starts in the north of France, after crossing the channel from Dover in England to Calais, driving down through France, over the Pyrenees into Spain, west into Portugal and then across the Continent to Italy and often beyond. There are numerous reasons young New Zealanders take this rite of passage—as well as seeing all the fantastic sights and tasting the delights of Europe's food and wine, it's relatively inexpensive. The Kombi is transport and accommodation all in one, cutting down significantly on costs. There is just one problem. As the Kombis become "antique", these trips are usually punctuated with numerous roadside sessions as the van sits idle, in no hurry to start, while you swelter in the hot sun. But do not let this deter you. Travelling Europe in your own vehicle means no public transport schedules to cramp your style, the ability to explore the quaint, off-the-beaten-track villages where the "real" locals live, freedom to not have to book accommodation in advance—you can nearly always get a campsite and can load your vehicle with cheap, fantastic regional wines and souvenirs. With these bonuses in mind, here are some suggestions for planning the great Europe road adventure. The key to a pleasurable driving experience is a good navigator and a driver with a cool head. If you do not feel relaxed driving around New Zealand's cities and highways, then you probably will not enjoy driving around Europe. As copilot to the driver, you need to read (and understand) maps, look out for turn-offs and keep the music playing. Language is not a big problem once a few essential terms are mastered. The biggest challenge is in the cities, where traffic can be chaotic and elaborate one-way systems and narrow, cobbled alleyways can make finding your destination hard work. It can be easier to leave the vehicle on the outskirts of town or in a camping ground and use public transport. This also avoids paying for costly parking.

单选题She gave us an ambiguous answer.

单选题Sleep Lets Brain File Memories To sleep. Perchance to file? Findings published online this week by the Proceedings of the National Academy of Sciences further support the theory that the brain organizes and stows memories formed during the day while the rest of the body is catching zzz's. Gyorgy Buzsaki of Rutgers university and his colleagues analyzed the brain waves of sleeping rats and mice. Specifically, they examined the electrical activity emanating from the somatosensory neocortex (an area that processes sensory information) and the hippocampus, which is a center for learning and memory. The scientists found that oscillation in brain waves from the two regions appear to be intertwined. So-called sleep spindles (bursts of activity from the neocortex) were followed tens of milliseconds later by beats in the hippocampus known as ripples. The team posits that this interplay between the two brain regions is a key step in memory consolidation. A second study, also published online this week by the Proceedings of the National Academy of Sciences, links age-associated memory decline to high glucose levels. Previous research had shown that individuals with diabetes suffer from increased memory problems. In the new work, Antonio Convit of New York University School of Medicine and his collaborators studied 30 people whose average age was 69 to investigate whether sugar levels, which tend to increase with age, affect memory in healthy people as well. The scientists administered recall tests, brain scans and glucose tolerance tests, which measure how quickly sugar is absorbed from the blood by the body's tissues. Subjects with the poorest memory recollection, the team discovered, also displayed the poorest glucose tolerance. In addition, their brain scans showed more hippocampus shrinkage than those of subjects better able to absorb blood sugar. "Our study suggests that this impairment may contribute to the memory deficits that occur as people age. " Convit says. "And it raises the intriguing possibility that improving glucose tolerance could reverse some age-associated problems in cognition" Exercise and weight control can help keep glucose levels in check, so there may be one more reason to go to the gym.

单选题A red flag was placed there as a token of danger.

单选题Though he was born and brought up in Japan, he can speak good English.A. smoothB. fluentC. fluidD. flowing

单选题In 1925 Clarence Darrow competently opposed William Jennings Bryan at the renowned Scopes' "Monkey Trial".A. adeptlyB. maliciouslyC. privatelyD. rashly

单选题We"ll do all we can to assist you.

单选题Paragraph 7_____

单选题First Aid First aid is emergency care for a victim of sudden illness or injury until more skillful medical treatment is available. It may save a life or improve certain vital signs including pulse, temperature, a clear airway(气道),and breathing , in minor emergencies, first aid may prevent a victim's condition form turning worse and provide relief from pain. First aid must be administered as quickly as possible. In the case of the critically injured, a few minutes can make the difference between complete recovery and loss of life. First-aid measures depend upon a victim's needs and the provider's level of knowledge and skill. Knowing what not to do in an emergency is as important as knowing what to do. Improperly moving a person with a neck injury, for example, can lead to permanent spinal(脊柱的) injury and paralysis(瘫痪). Despite the variety of injuries possible, several principles of first aid apply to all emergencies. The first step is to call for professional medical help. The victim, if conscious, should be reassured that medical aid has been requested, and asked for permission to provide any first aid. Next, assess, the scene, asking other people or the injured person's family or friends about details of the injury or illness, any care that may have already been given ,and preexisting conditions such as diabetes(糖尿病) or heart trouble. The victim should be checked for a medical bracelet(手镯)or card that describes special medical conditions. Unless the accident scene becomes unsafe or the victim may suffer further injury, do not move the victim. First aid requires rapid assessment of victims to determine whether life-threatening conditions exist. One method for evaluating a victim's condition is known by the acronym(首字母缩写词)ABC, which stands for: A—Airway: Is it open and clear? B—Breathing: Is the person breathing? Look, listen, and feel for breathing. C—Circulation: Is there a pulse? Is the person bleeding externally? Check skin color and temperature for additional indications of circulation problems.

单选题It's {{U}}sensible{{/U}} to start any exercise program gradually at first. A. workable B. reasonable C. possible D. available

单选题We were shocked to find that Mary didn't know the guest's name.

单选题A Memory Drug? It"s difficult to imagine many things that people would welcome more than a memory-enhancing drug. A memory enhancer could help eliminate forgetting associated with aging and disease. Furthermore, such a drug could help people remember past experiences more 1 and help us acquire new information more easily for school and at work. As scientists learn more about 2 , we are closing in on this tantalizing goal. Some of the most exciting evidence comes from research that has built on earlier findings linking LTP and memory to identify a gene that improves memory in mice. The gene makes a protein that assists the NMDA receptor, which plays an important 3 in long-term memory by helping to initiate LTP. Mice bred to have extra copies of this gene showed more activity in their NMDA receptors, more LTP, and 4 performance on several different memory tasks—learning a spatial layout, recognizing familiar objects, and recalling a fear-inducing shock. If these basic insights about genes, LTP, and the synaptic basis of memory can be 5 to people-and that remains to be seen—they could pave the way for memory-enhancing treatments. 6 steroids for bulking up the muscles, these drugs would bulk up memory. As exciting as this may 7 , it also raises troubling issues. Consider the potential educational implications of memory-enhancing drugs. If memory enhancers were available, children 8 used them might be able to acquire and retain extraordinary amounts of information, allowing them to progress far more rapidly in 9 than they could otherwise. How well could the brain handle such an onslaught of information? What happens to children who don"t have access to the latest memory enhancers? Are they left behind in school—and as a result handicapped later in life? What are the potential implications of memory-enhancing drugs for the workplace? Imagine that you are 10 for a job that requires a good memory, such as a manager at a technology company or a sales position that requires remembering customers" names as well as the attributes of different products and services. Would you take a memory-enhancing drug to increase your chances of landing the position? 11 people who felt uncomfortable taking such a drug find themselves cut out of lucrative career opportunities? Memory drugs might also help take the sting out of disturbing memories that we wish we could forget 12 can"t. The 2004 hit movie Eternal Sunshine of the Spotless Mind told the story of a young man seeking just such freedom 13 the painful memories of a romantic breakup. As you will see in the section on persistence later in the chapter, emotionally arousing events often create intrusive memories, and researchers have already muted emotional memories with drugs that block the action of key hormones. Should emergency workers who must confront horrifying accident scenes that can 14 them with persisting memories be provided with such drugs? Should such drugs be given to rape victims who can"t forget the trauma? Memory drugs might provide some relief to such individuals. But could they also interfere with an individual"s ability to assimilate and come to terms with a difficult experience? We may find ourselves 15 these kinds of questions in the not-too-distant future.

单选题When does the next train depart ?

单选题Up to now, the work has been easy. A. So B. So long C. So far D. So that

单选题The bird flew upward and dropped the shellfish onto the rock to ______ it open.A. cutB. pressC. breakD. shake

单选题You must try to wipe out the memory of these horrible events.

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

单选题Bees and Colour On our table in the garden we put a blue card, and all around this blue card we put a number of different grey cards. These grey cards are of all possible shades of grey and include white and black. On each card a watch-glass is placed. The watch-glass on the blue card has some syrup(果汁) in it, all the others are empty. After a short time bees find the syrup, and they come for it again and again. Then, after some hours, we take away the watch-glass of syrup which was on the blue card and put an empty one in its place. Now what do the bees do? They still go straight to the blue card, although there is no syrup there. They do not go to any of the grey cards, in spite of the fact that one of the greycards is of exactly the same brightness as the blue card. Thus the bees do not mistake any shade of grey for blue. In this way we have proved that they do really see blue as a colour. We can find out in just the same way what other colours bees can see. It turns out that bees can see various colours, but these insects differ from us as regards their colour-sense in two very interesting ways. Suppose we train bees to come to a red card, and, having done so, we put the red card on the table in the garden among the set of different grey cards. This time we find that the bees mistake red for dark grey or black. They cannot distinguish between them. This means that red is not a colour at all for bees; for them it is just dark grey or black. That is one strange fact; here is another. A rainbow is red on one edge, violet on the other. Outside the violet of the rainbow there is another colour which we cannot see at all. This colour beyond the violet ,invisible to us, is called the ultra-violet. Although it is invisible, we know that the ultra-violet is there because it affects a photographic plate. Now, although we are unable to see ultra violet light , bees can do so; for them ultra-violet is a colour. Thus bees see a colour which we cannot even imagine. This has been found out by training bees to come for syrup to various parts of a spectrum, or artificial rainbow, thrown by a prism on a table in a dark room. In such an experiment the insects can be taught to fly to the ultra-violet, which for us is just darkness.

单选题Smoking is not permitted in the office.