单选题She felt hurt by my words, but it wash' t really out of my intention.A. purposeB. indicationC. implicationD. invasion

单选题If headaches only {{U}}occur{{/U}} at night, lack of fresh air is often the cause. A. deliver B. fall C. happen D. arrive

单选题 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, hut 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 wail 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The old concerns lose importance and some of them Uvanish/U altogether;

单选题During his lifetime he was able to {{U}}accumulate{{/U}} quite a fortune. A. control B. spend C. collect D. exchange

单选题阅读下面的短文，文中有15处空白，每处空白给出4个选项，请根据短文的内容从4个选项中选择1个最佳答案。 One of the most important technological developments during the 1980s has been the emergence of optical fiber communication as a major international industry. One indication of the{{U}} (51) {{/U}}of this development is the total{{U}} (52) {{/U}}of installed fiber, which was estimated to be 3.2 million kilometers in the U.S. alone by the end of 1987. Over 90% of this fiber was placed.{{U}} (53) {{/U}}during the time period of 1982—1987. Long-haul trunk installations(长途干线设施) have dominated,{{U}} (54) {{/U}}for about 95% of the fiber in the U.S. In the early 1950s the researchers who produced the first clad glass optical fibers were not{{U}} (55) {{/U}}of using them. for communications.{{U}} (56) {{/U}} , fiber optics was already a well-established commercial technology when the famous paper by Kao and Hockham,{{U}} (57) {{/U}}the use of low-loss optical fibers for communication, appeared in 1966. The first low-loss silica fiber was described in a publication which appeared in October of 1970. The date of this publication is sometimes{{U}} (58) {{/U}} as the beginning of the era of fiber communication. Although this development did receive{{U}} (59) {{/U}}attention in the research community at- the time, it was far from inevitable that a major industry would evolve. The technological barriers appeared{{U}} (60) {{/U}}because there were serious doubts as to{{U}} (61) {{/U}}these fiber components could ever be produced economically enough, but the market potential was very significant.{{U}} (62) {{/U}}, research and development activity expanded rapidly, and a number of important issues were{{U}} (63) {{/U}}during the early 1970s. During the middle and late 1970s, the rate of progress towards marketable products accelerated as the emphasis {{U}}(64) {{/U}}from research to engineering. Fibers with losses approaching the Payleigh limit of 2 dB/km at a wavelength of 0.8um were produced. By 1980 improvement in component performance, cost, and reliability led to major commitments{{U}} (65) {{/U}}the part of telephone companies.

单选题It is possible to approach the problem in a different way.

单选题He has trouble understanding that other people judge him by his social skills and {{U}}conduct{{/U}}. A. style B. behavior C. mode D. attitude

单选题{{B}}第二篇{{/B}} Black Holes Trigger Stars' Self-destruction Scientists have long understood that super massive (大块的) black holes weighing. Millions or billions of suns can tear apart stars that come too close. The black hole's gravity (地心引力) pulls harder on the neatest part of the star, an imbalance that pulls the star apart over a period of minutes or hours, once it gets close enough. Scientists say this uneven pulling is not the only hazard (冒险) facing the star. The strain of these unbalanced forces can also trigger (触发) a nuclear explosion powerful enough to destroy the star from within. Matthieu Brassart and Jean-Pierre Luminet of the Observatoire of the Paris in Meudon, France, carried out computer simulations of the final moments of such an unfortunate star's life, as it veered towards a supermassive black hole. When the star gets Close enough, the uneven forces flatten it into a pancake shape. Some previous studies had suggested this flattening would increase the density and temperature inside the star enough to trigger intense nuclear reactions that would tear it apart (扯开). But other studies had suggested that the picture would he complicated by shock waves generated during the flattening process and that not nuclear explosion should occur. The new simulations investigated the effects of shock waves in detail, and fund that even when their effects are included; the conditions favor a nuclear explosion. "There will be an explosion of the star. It will be completely destroyed," Brassart says. Although the explosion obliterates the star, it saves some of the start's matter from being devoured by the black hole. The explosion is powerful enough to hurt much of the star's matter out of the black hole's reach, he says. The devouring of stars by black holes may already have been observed, although at a much later stage. It is thought that several months after the event that rips the star apart, its matter starts swirling into the hole itself. It heats up as it does so, releasing ultraviolet light and X-rays. If stars disrupted (使分裂) near black holes really do explode, then they could in principle allow these events to be detected at a much earlier stage, says Jules Halpern of Columbia University in New York, US. "It may make it possible to see the disruption of that star immediately if it gets hot enough. " Brassart aggress. "Perhaps it can be observed in the X-rays and gamma rays, but it's something that needs to be more studied , "he says. Supernova researcher Chris Fryer of the Los Alamos National Laboratory in Los Almos, New Mexico, US, says the deaths of these stars are difficult to simulate, and he is not sure whether the researchers have proven their case they exploded in the process.

单选题For many years the poor woman was Ua virtual prisoner/U in her own home.

单选题Norman Blarney is an artist of deep Uconvictions/U.

单选题One factor that can influence consumers is their mood state. Mood may be defined (51) a temporary and mild positive or negative feeling that is generalized and not tied to any particular circumstance. Moods should be (52) from emotions which are usually more intense, (53) to specific circumstances, and often conscious. In one sense, the effect of a consumer's mood can be thought of in (54) the same way as can our reactions to the (55) of our friends-when our friends are happy and "up" ,that tends to influence us positively, (56) when they are "down", that can have a (57) impact on us. Similarly, consumers operating under a (58) mood state tend to react to stimuli (刺激因素) in a direction (59) with that mood state. Thus, for example, we should expect to see consumers in a positive mood state evaluate products in more of a (60) manner than they would when not in such a state. (61) ,mood states appear capable of (62) a consumer's memory. Moods appear to be (63) influenced by marketing techniques. For example, the rhythm, pitch, and volume of music has been shown to influence behavior such as the (64) of time spent in supermarkets or intensions to purchase products. In addition, advertising can influence consumers' moods which, in (65) , are capable of influencing consumers' reactions to products.

单选题Marxism doctrine was spelled out in the Communist Manifesto. A. evaluated B. detailed C. supported D. mentioned

单选题Most of the pioneers of low-temperature physics expected gases to liquefy, but none of them predicted superconductivity. This phenomenon was discovered in 1911 by Onnes while he was studying frozen mercury. More than 40 years passed before physicists were able to offer an explanation for superconductivity. The accepted theory, developed in the 1950s, holds that the fundamental behavior of electrons changes at very low temperatures because of the effects of quantum mechanics. Electrons are tiny particles that make up the outer part of an atom, circling rapidly around the nucleus of the atom. In a regular conductor—a metal that conducts an electric current—the outermost electrons are not bound tightly to the atoms, and so they move around relatively freely. The flow of these electrons is an electric current. At normal temperatures, a conductor's electrons cannot move completely freely through the metal because they are "bumped around" by the metal's atoms. But according to the leading theory of superconductivity, when a metal is very cold, electrons form pairs. Then, like couples maneuvering on a crowded dance floor but never colliding, the paired electrons are able to move unimpeded through the metal. In pairing up, it seems, the electrons are able to "blend together" and move in unison without resistance. This explanation seems to account for superconductivity at extremely low temperatures, but in 1986 scientists in Switzerland found that some metal-containing ceramics are superconductors at much higher temperatures. By 1992, scientists had developed ceramics that become superconducting at - 297'F, and some researchers speculated that room-temperature superconductors may be possible. Scientists are still trying to formulate a theory for high-temperature superconductivity. The new ceramic materials can be maintained at their superconducting temperatures, with relatively inexpensive liquid nitrogen rather than the much colder and much more costly liquid helium required by metal superconductors. The cost difference could make superconductivity practical for many new technologies. For example, magnetically levitated trains, which require superconducting electromagnets, would be much cheaper to build than they are now. Superconducting devices might also be used for advanced power transmission lines and in new types of compact, ultrafast computers. But for the time being, superconductivity is finding application mostly in scientific research and in some kinds of medical imaging devices.

单选题Facebook Wants to "Listen" to Your Music and TV Facebook is to release a new feature on its mobile app that "listens" to your music and TV shows. If the song or show is recognized by the app, users can publish the information on their profile or to selected friends. The service hopes to take advantage of the "second screen" trend, which sees fans of TV shows in particular sharing their experiences on social networks. However, some users have privacy concerns. The feature, which will be available in a few weeks" time, uses the microphones inside users" smartphones to detect nearby music or TV shows. As the user begins writing a status update, a small animated icon will appear at the top of the app. If the app detects the appropriate audio signals and finds a match from its database, the user can then share what he or she is watching or listening to. Facebook says the feature can be turned off at any time, the audio recording is not stored anywhere and the device cannot identify background noise or conversations. "If you share music, your friends can see a 30-second preview of the song. For TV shows, the story in News Feed will highlight the specific season and episode you"re watching," Facebook said in a statement. The company hopes this new method of sharing user listening and watching habits will take advantage of the five billion status updates related to TV and music experiences that the social networking giant sees on a yearly basis. However, automating part of the sharing process has left some users suspicious, with Nicole Simon commenting on TechCrunch that: "While the idea is nice and technology really interesting, I have no interest in Facebook "observing" my audio and surrounding. Yes, it starts currently as opt-in, and only on occasion, but there is no trust from my side for even that." The BBC understands that this new feature was not specifically designed to enhance Facebook"s advertising. However, the company could push an advertisement to a user"s phone based on their tracked listening habits. This is in keeping with Facebook"s current approach to advertising, which uses publicly provided information on users" profiles to push advertisements that are more relevant to each individual user. The basic idea behind Facebook"s feature is not a new one—since 2002 Shazam, which has recently seen a $3 million investment from Sony Music Entertainment, has been providing a similar audio recognition service, with its website describing itself as "a mobile app that recognizes music and TV around you". Facebook"s much larger user base could pose a future threat to the comparatively smaller company.

单选题As he had already {{U}}been accustomed{{/U}} to living in the countryside, Jackson refused to move to the city.

单选题This remarkable technology provides far greater Uclarity/U than conventional x-ray.

单选题Sleep Necessary for Memories Burning the midnight oil before an exam or interview does harm to the performance according to a recent research which found that sleep is necessary for memories to be taken back into the brain. A．good night's sleep within 30 hours of trying to remember a new task is a required condition of having good recall in the weeks ahead, scientists have found. The research, published in the December issue of Nature Neuroscience, showed that it was the act of sleep, rather than the simple passage of time, that was critical for long- term memory formation. "We think that getting that first night's sleep starts the process of memory consolidation (巩固)," said Robert Stickgold, a sleep researcher at Harvard Medical School who conducted the latest study. "It seems that memories normally wash out of the brain unless some process nails them down. My suspicion is that sleep is one of those things that does the nailing down," Professor Stickgold said. With about one in five people claiming that they are so chronically short of sleep that it affects their daily activities, the latest work emphasizes the less well-understood side effect—serious memory impairment (损害). Volunteers in an experiment found it easier to remember a memory task if they were allowed to sleep that night. But for those kept awake, no amount of subsequent sleep made up for the initial loss. Professor Stickgold's team trained 24 people to identify the direction of three diagonal (斜线形的) bars flashed for a sixtieth of a second on a computer screen full of horizontal (水平的) stripes. Half of the subjects were kept awake that night, while the others slept. Both groups were allowed to sleep for the second and third nights to make up for any differences in tiredness between the volunteers. Those who slept the first night were significantly and consistently better at remembering the task while the second group showed no improvement despite enjoying two nights of catch-up sleep.

单选题Mary looked pale and weary .

单选题Which of the following statements is NOT true, according to the passage?