语言类
公务员类
工程类
语言类
金融会计类
计算机类
医学类
研究生类
专业技术资格
职业技能资格
学历类
党建思政类
全国职称英语等级考试
大学英语考试
全国英语等级考试(PETS)
英语证书考试
英语翻译资格考试
全国职称英语等级考试
青少年及成人英语考试
小语种考试
汉语考试
理工类职称英语等级考试
综合类职称英语等级考试
理工类职称英语等级考试
卫生类职称英语等级考试
单选题A beautiful woman Uattended/U to me in that store yesterday.
进入题库练习
单选题The project required ten years of {{U}}diligent{{/U}} research. A. hardworking B. social C. basic D. scientific
进入题库练习
单选题Please Fasten Your Seatbelts Severe turbulence (湍流) can kill aircraft passengers. Now, in test flights over the Rocky Mountains, NASA (美国航空航天局) engineers have successfully detected clear-air turbulence up to 10 seconds before an aircraft hits it. Clear-air turbulence often catches pilots by surprise. Invisible to radar, it is difficult to forecast and can hurl (用力抛出去) passengers about the cabin. In December 1997, one passenger died and a hundred others were injured when unexpected rough air caused a United Airlines flight over the Pacific to drop 300 meters in a few seconds. However, passengers can avoid serious injury by fastening their seatbelts. "It is the only antidote (对策) for this sort of thing," says Rod Bogue, project manager at NASA"s Dryden Flight Research Center in Edwards, California. The centre"s new turbulence detector is based on lidar, or laser radar. Laser pulses are sent ahead of the plane and these are then reflected back by particles in the air. The technique depends on the Doppler effect. The wavelength of the light shifts according to the speed at which the particles are approaching. In calm air, the speed equals the plane"s airspeed. But as the particles swirl (打漩) in rough air, their speed of approach increases or decreases rapidly. The rate of change in speed corresponds to the severity (激烈程度) of the turbulence. In a series of tests that began last month, a research jet flew repeatedly into disturbed air over the mountain ridges (山脉) near Pueblo, Colorado. The lidar detector spotted turbulence between 3 and 8 kilometers ahead, and its forecasts of strength and duration corresponded closely with the turbulence that the plane encountered. Bogue says that he had "a comfortable amount of time" to fasten his seatbelt. The researchers are planning to improve the lidar"s range with a more powerful beam. The system could be installed on commercial aircraft in the next few years.
进入题库练习
单选题The room is gloomy but tidy.
进入题库练习
单选题They all agreed that the changes that have taken place are substantial.A. significantB. superficialC. inadequateD. inevitable
进入题库练习
单选题We were {{U}}shocked{{/U}} to find that Mary did't know her guest's name.
进入题库练习
单选题Sonic Device The other day, Dr. Robert Smith, who is blind, took a remarkable stroll through the campus of the University of California at Santa Barbara. As Dr. Smith walked along the campus, places and impediments (障碍物) in his path seemed to call out their names to him -- "library here, library here", "bench here, bench here". Dr. Smith was testing a prototype (样机) navigation system for the blind that anounced the surrounding objects through stereo headphones that were mounted to a computer in his back-pack, creating a virtual reality landscape(仿真影像). The information came not from some miniature radar but from the signals broadcast by the military's network of gloal positioning satellites(全球定位卫星). One day, its developers hope, miniaturized(小型化的) versions of this navigation devices, which now weighs twenty-eight pounds, will help the blind navigate unfamiliar neighborhoods. "With this system you do not need to know a thing in advance about where you are going", said Dr. Roberta Klatzky, a psychologist at Carnegie-Mellon University who is working with Dr. Smith to develop the navigating device. Dr. Michael Oberdor of the National Eye Institute said, "A blind person could walk clown the street and know not just he was at 80th and Broadway, but what stores are around, and that Zabar's delicatessen(熟食店) was up ahead. This navigation system tells you not just where there are obstacles, but your overall location geographically. " It lets blind users construct a mental map of new surroundings and learn their way around. The navigation system uses signals from a computerized map to create a "virtual acoustic display(仿真声音显示). This is a talking map in which large objects seem to announce themselves in the headphones with the precise timing and loudness that would be the case if the objects were actually making a sound. This allows the blind person to sense immediately his or her distance or direction, and use that information for guidance. While no one knows whether it is because blind people tend to develop a sharper sense of hearing, those who have tried the system say that they quickly adapt to locating an object through the sounds. "One of the crucial features of this system is that it takes advantage of sensory paychophysics (感官心理物理学) -- how the brain interprets signals from outside to make a map of your surroundings so you can navigate, " Dr. Oberdor said.
进入题库练习
单选题The mail was delayed for two days because of the snow-storm. A. held in B. held up C. held down D. held off
进入题库练习
单选题Many visitors find the tempo of life here very difficult. A. kind B. growth C. speed D. spectacle
进入题库练习
单选题下面的短文后列出了7个句子,请根据短文的内容对每个句子做出判断:如果该句提供的是正确信息,请选择A;如果该句提供的是错误信息,请选择B;如果该句的信息文中没有提及,请选择C。 Irish Dolphins May Have a Unique Dialect Irish scientists monitoring dolphins living in a river estuary in the southwest of the country believe they may have developed a unique dialect to communicate with each other. The Channel Dolphin and Wildlife Foundation (SDWF) has been studying a group of up to 120 bottle-nose dolphins in the River Shannon using vocalisations collected on a computer in a cow shed near the River Shannon. As part of a research project, student Ronan Hickey digitised and analysed a total of 1,882 whistles from the Irish dolphins and those from the Welsh dolphins on a computer and separated them into six fundamental whistle types and 32 different categories. Of the categories, he found most were used by both sets of dolphins—but eight were only heard from the Irish dolphins. "We are building up a catalogue of the different whistle types they use and trying to associate them with behaviour like foraging, resting, socialising and the communications of groups with calves," project leader Simon Berrow said. "Essentially we are building up what is like a dictionary of words they use or sounds they make. " Berrow, a marine biologist, said the dolphins' clicks are used to find their way around and locate prey. The whistles are communications. "They do a whole range of other sounds like barks, groans and a kind of gunshot. " He said. "The gunshot is an intense pulse of sound. Sperm whales use it to stun their prey. " "When I first heard it I was surprised as I thought sperm whales were the only species who used it. We can speculate the dolphins are using it for the same reason as the sperm whales. " Berrow said. References in local legend indicate there have been dolphins in the Shannon estuary for generations and they may even have been resident there as far back as the 6th century. They are regularly seen by passengers on the Shannon ferry and an estimated 25,000 tourists every year take special sightseeing tours on local boats to visit them.
进入题库练习
单选题It is Uridiculous/U to dispute about such things.
进入题库练习
单选题They have a far beaer yield than any other year.A. expectationB. soilC. climateD. harvest
进入题库练习
单选题He obviously displays a great appreciation for some of your poems.A. consentB. admirationC. respectD. pleasure
进入题库练习
单选题Which of the following is NOT mentioned as a reason for the disrupted sleep of travelers?
进入题库练习
单选题The Ucontempt /U he felt for his fellow students was obvious
进入题库练习
单选题I feel regret about what"s happened.
进入题库练习
单选题The city has decided to do away with all the old buildings in its center.
进入题库练习
单选题{{B}}第二篇{{/B}} {{B}} What is Cold?{{/B}} How cold is cold? It all depends on who is talking. To us ordinary people nothing in the world maybe so cold as failing through the ice on a frozen lade, or huddling(卷缩)on a windswept mountain hoping to be rescued in the dead of winter. Some may even think they are freezing to death when rushing under an ice-cold shower just out of a warm bed. Indeed, we all know what cold means. Arctic(北极) .explorers would laugh at such ideas. Down in the Antarctic(南极), where scientists of many nations spend very dark months living on a sheet of ice two miles thick, the temperature spends most of its time at 50or60 degrees Fahrenheit below zero, often with hundred-mile winds and heavy snowstorms. This is the cold that is cold, to them. Space people have still another standard. The coldest place in which a person can live and survive is some 400 degrees hotter than space itself,". However, the coldest place in earth-colder even than space-is inside a machine called a cryostat(低温保持器). Here, scientists and engineers in thousands of laboratories and factories in many parts of the world regularly make cold that turns the South Pole's worst into a pleasant summer day. They are inching toward such cold that there is no temperature at all-down a frozen valley that leads to Absolute Zero, 459.67 degrees Fahrenheit below our zero of a cold winter's day.
进入题库练习
单选题Will Quality Eat up the U. S. Lead in Software? If U. S. software companies don't pay more attention to quality, they could kiss their business good-bye. Both India and Brazil are developing a world-class software industry. Their weapon is quality and one of their jobs is to attract the top U. S. quality specialists whose voices are not listened to in their country. Already, of the world's 12 software houses that have earned the highest rating in the world, seven are in India. That's largely because they have used new methodologies rejected by American software specialists. For example, for decades, quality specialists, W · Edwards Deming and J. M. Juran had urged U. S. software companies to change their attitudes to quality. But their quality call mainly fell on deaf ears in the U. S—but not in Japan. By the 1970s and 1980s. Japan was grabbing market share with better, cheaper products. They used Deming's and Juran's ideas to bring down the cost of good quality to as little as 5% of total production costs. In U. S. factories, the cost of quality then was 10 times as high: 50%. In software, it still is. Watts S. Humphrey spent 27 years at IBM heading up software production and then quality assurance. But his advice was seldom paid attention to. He retired from IBM in 1986. In 1987, he worked out a system for assessing and improving software quality. It has proved its value time and again. For example, in 1990 the cost of quality at Raytheon Electronics Systems was almost 60% of total software production costs. It fell to 15% in 1996 and has since further dropped to below 10%. Like Deming and Juran, Humphrey seems to be winning more praises overseas than at home. The Indian government and several companies have just founded the WaRs Humphrey Software Quality Institute at the Software Technology Park in Chennai, India. Let's hope that U. S. 1 ead in software will not he eaten up by its quality problems.
进入题库练习
单选题Stage Fright Fall down as you come onstage. That"s an odd trick. Not recommended. But it saved the pianist Vladimir Feltsman when he was a teenager back in Moscow. The veteran cellist (大提琴演奏家) Mstislav Rostropovich tripped him purposely to cure him of pre-performance panic. Mr. Feltsman said, "All my fright was gone. I already fell. What else could happen?" Today, music schools are addressing the problem of anxiety in classes that deal with performance techniques and career preparation. There are a variety of strategies that musicians can learn to fight stage fright and its symptoms: icy fingers, shaky limbs, racing heart, blank mind. Teachers and psychologists offer wide-ranging advice, from basics like learning pieces inside out, to mental discipline, such as visualizing a performance and taking steps to relax. Don"t deny that you"re jittery (紧张不安的), they urge; some excitement is natural, even necessary for dynamic playing. And play in public often, simply for the experience. Psychotherapist Diane Nichols suggests some strategies for the moments before performance, "Take two deep abdominal breaths, open up your shoulders, then smile," she says. "And not one of these "please don"t kill me" smiles. Then choose three friendly faces in the audience, people you would communicate with and make music to, and make eye contact with them." She doesn"t want performers to think of the audience as a judge. Extreme demands by mentors or parents are often at the root of stage fright, says Dorothy Delay, a well- known violin teacher. She tells other teachers to demand only what their students are able to achieve. When Lynn Harrell was 20, he became the principal cellist of the Cleverland Orchestra, and he suffered extreme stage fright. "There were times when I got so nervous. I was sure the audience could see my chest responding to the throbbing. It was just total panic. I came to a point where I thought, "If I have to go through this to play music, I think I"m going to look for another job."" Recovery, he said, involved developing humility-recognizing that whatever his talent, he was fallible, and that an imperfect concert was not a disaster. It is not only young artists who suffer, of course. The legendary pianist Vladimir Horowitz"s nerves were famous. The great tenor Franco Corelli is another example. "They had to push him on stage," Soprano Renata Scotto recalled. Actually, success can make things worse. "in the beginning of your career, when you"re scared to death, nobody knows who you are, and they don"t have any expectations," Soprano June Anderson said. "There"s less to lose. Later on, when you"re known, people are coming to see you, and they have certain expectations. You have a lot to lose." Anderson added, "I never stop being nervous until I"ve sung my last note."
进入题库练习