单选题2. A Sophisticated Device for Sophisticated Communication As wireless communication has become more sophisticated, consumers have more and more choices of ways to communicate and organize their lives at the same time. So, what kind of device do most people want to carry in the future? A Personal Digiml Assistant(PDA) that talks or a cell phone that can handle data? There's evidence that smart cell phones are winning the hearts of consumers. There are certainly lots more cell phones in people's hands. Sales of cell phones still outnumber those of PDAs. The simple reason for this is that users find wireless phones convenient and easy. There's no special knowledge required to use them; everybody already knows how to make phone calls. To maintain their advantage, however cell—phone manufacturers should continue to design their phones primarily for voice communications. Other applications need to complement voice features, not compromise them. There are a number of design criteria that cell phone manufacturers must take into consideration as they are essential to successful market appeal. Cell phone designers need to keep in mind that people buy these devices first to communicate, not to compute, so they need to remain easy to use. Therefore, most importantly, new combination devices need to look like phones. The familiar look of cell phones also makes it easier for technophobes, who fear new gadgets, to accept devices with more complex capabilities. The average phone user prefers a simple keypad, not a stylus for writing on a screen. Small size is also valued. After all, convenience is what has made cell phones so popular in the first place. Given these criteria, however, the appeal of technology is to offer the customer innovation— something new to capture their imagination. So, what are manufacturers adding to cell phones? Anything that requires a lot of typing or a large screen won't work. Word processing, spreadsheets, or even most web surfing isn't practical. Successful smart-phone applications need only to add to the convenience of phones. Making it even easier for the consumer to stay in touch and be productive is the priority. As such, some useful applications could be personal information management programs, such as an address book, calendar, or a" to-do" list, which automatically communicate with the user's home—or office—based PC. Also, phones can be programmed for access to specific Internet data and functions that the user chooses. They can offer phone directory searches and driving directions. More features might include short messaging services, e-mail, and fax.

单选题Shopping for Clothes Shopping for clothes is not the same experience for a man as it is for a woman. A man goes shopping because he needs something. His purpose is settled and decided in 1 . He knows what he wants, and his 2 is to find it and buy it. All men simply walk into a shop and ask the assistant for what they want. If the shop has it in stock, the deal can be and often is completed in less than five minutes, with hardly any chat and to everyone"s 3 . For a man, slight problems may begin when the shop does not have what he wants. In that 4 the salesman tries to sell the customer something else—he offers the nearest to the article required. Good salesman brings out such a substitute with 5 : "I know this jacket is not the style you want, sir, but would you like to try it for size. It 6 to be the colour you mentioned." Few men have 7 with this treatment, and the usual response is. "This is the right colour and may be the right size, but I should be 8 my time and yours by trying it on." For a woman, buying clothes is always done in the 9 way. Her shopping is not often 10 on need. She has never fully decided what she wants, and she is only "having a look round". She is always open to persuasion, willing to try 11 any number of things. Uppermost in her mind is the thought of finding something that 12 thinks suits her. Most women have an excellent sense of value and are always on the look-out for the unexpected 13 . Faced with a roomful of dresses, a woman may easily spend an hour going from one rail to another 14 selecting the dresses she wants to try on. It is a tiresome process, but apparently a(n) 15 one. Most dress shops provide chairs for the waiting husbands.

单选题Such a database would be extremely costly to {{U}}set up{{/U}}. A. transfer B. destroy C. establish D. update

单选题The ship left New York on her maiden voyage.

单选题Most of the dreadful eruptions of Mount Saint Helens took place in early May.

单选题It is absurd to predict that the sun will not rise tomorrow.

单选题How sleep helps us consolidate memories is still largely a mystery. A recent study from the University of Lǔbeck, in Germany, offers one clue. Subjects were given a list of 46 word pairs to memorize, just before sleep. Then when they reached the deepest stages of sleep, electrical currents were sent through electrodes on their heads to induce very slow brain waves. Such slow waves were induced at random in the brains of one group of subjects, but not another. The next morning, the slow-wave group had better recall of the words. Other types of memory were not improved, and inducing the slow waves later in the night did not have the same effect. Why and how the slow waves improved memory is not yet understood, but they are thought to alter the strengths of chemical connections, or synapses, between specific pairs of nerve cells in the brain. Memories are "stored" in these synapses: changing the strength of the synapses increases the strength of the memories they store. Slow waves functioned in the subjects' brains in the experiment whenA. they were given a list of words before sleep.B. they reached the deepest stages of sleep.C. they were connected to electrical currents.D. they were asked to recall the words the next mornin

单选题Mary called me up very late last night. A. praised me B. visited me C. telephoned me D. waked me

单选题Jensen is a dangerous man, and can be very brutal .

单选题Cosmos 2251 was an ordinary satellite designed to transmit signals across the vast Russian landmass. Launched in 1993, it would appear every 90 minutes or so over the northern skies, relay electronic blips of information among a network of satellites and ground stations like a hockey player passing the puck (冰球运动中当球用的橡胶圆盘), and disappear over the southern horizon. Cosmos was designed toA. play hockey with human players.B. guard the Russian landmass.C. patrol over the Russian sky.D. send information back to stations.

单选题Reading the job ad, he wondered whether he was eligible to apply for it.

单选题We have to take some ______ to put it right.A. decisionsB. advantagesC. sidesD. measures

单选题I didn't help him. I would have Uhowever/U didn't have the money.

单选题The ice is not thick enough to bear the weight of a tank.

单选题TapeStore: A New Tape Storage System TapeStore is a new kind of tape storage system which can store up to 6,000 computer tapes. No other tape storage system can hold as many computer tapes as TapeStore. The tapes look exactly like video cassettes. Many hundreds of data files can be stored on each tape, up to a maximum of 500 million bytes (字节) of data. If you stored the same amount of information on paper, you would need nearly 4.5 billion printed pages. The machine is a tall black box with a mechanical arm. The machine is 2.5 meters high and 3.0 meters wide. This is how it works. Each tape has a code printed on it. You feed the code number into TapeStore, which then looks for the code. As soon as TapeStore locates the code, the arm reaches in and pulls out the tape. The system is very fast. It takes the mechanical arm about 10 seconds to find the tape it is looking for. The machine then searches the tape to extract (提取) the required file, and this takes less than a minute. A human technician would have to locate and remove the tape by hand, and could take at least an hour to find the right file on the tape. Some of the world"s biggest companies, including banks, insurance companies, airlines, telephone companies, utilities and computer centers, have bought the system. They like it particularly because the system guarantees the security of their data. TapeStore was originally developed in Canada and is now being marketed worldwide. In Europe alone, 750 Tape Stores have already been installed at a cost of 480,000 dollars each.

单选题who are mostlikely to benefit from the study?

单选题Superconductor Ceramic (陶瓷) An underground revolution begins this winter. With the flip (轻击) of a switch, 30,000 homes in one part of Detroit will soon become the first in the country to receive electricity transmitted by ice-cold high-performance cables. Other American cities are expected to follow Detroit"s example in the years ahead, which could conserve enormous amounts of power. The new electrical cables at the Frisbie power station in Detroit are revolutionary because they are made of superconductors. A superconductor is a material that transmits electricity with little or no resistance. Resistance is the degree to which a substance resists electric current. All common electrical conductors have a certain amount of electrical resistance. They convert at least some of the electrical energy passing through them into waste heat. Superconductors don"t. No one understands how superconductivity works. It just does. Making superconductors isn"t easy. A superconductor material has to be cooled to an extremely low temperature to lose its resistance. The first superconductors, made more than 50 years ago, had to be cooled to-263degrees Celsius before they lost their resistance. Newer superconducting materials lose their resistance at-143 degrees Celsius. The superconductors cable installed at the Frisbie station is made of a ceramic material that contains copper, oxygen, bismuth (铋) , strontium (锶) , and calcium (钙). A ceramic is a hard, strong compound made from clay or minerals. The superconducting ceramic has been fashioned into a tape that is wrapped lengthwise around a long tube filled with liquid nitrogen. Liquid nitrogen is super cold and lowers the temperature of the ceramic tape to the point where it conveys electricity with zero resistance. The United States loses an enormous amount of electricity each year to resistance. Because cooled superconductors have no resistance, they waste much less power, other cities are watching the Frisbie experiment in the hope that they might switch to superconducting cable and conserve power, too.

单选题The researchers have just {{U}}completed{{/U}} a study of driving situations. A. started B. finished C. changed D. made

单选题The project required ten years of diligent research.

单选题World Crude Oil Production May Peak a Decade Earlier Than Some Predict? In a finding that may speed efforts to conserve oil, scientists in Kuwait predict that world conventional crude oil production will peak in 2014. This prediction is almost a decade earlier than some other predictions. Their study is in ACS" Energy & Fuels. Ibrahim Nashawi and colleagues point out that rapid growth in global oil consumption has sparked a growing interest in predicting "peak oil". "Peak oil" is the point where oil production reaches a maximum and then declines. Scientists have developed several models to forecast this point, and some put the date at 2020 or later. One of the most famous forecast models is called the Hubbert model. It assumes that global oil production will follow a bell shaped curve. A related concept is that of "Peak Oil". The term "Peak Oil" indicates the moment in which worldwide production will peak, afterwards to start on irreversible decline. The Hubbert model accurately predicted that oil production would peak in the United States in 1970. The model has since gained in popularity and has been used to forecast oil production worldwide. However, recent studies show that the model is insufficient to account for more complex oil production cycles of some countries. Those cycles can be heavily influenced by technology changes, politics, and other factors, the scientists say. The new study describes development of a new version of the Hubbert model that provides a more realistic and accurate oil production forecast. Using the new model, the scientists evaluated the oil production trends of 47 major oil-producing countries, which supply most of the world"s conventional crude oil. They estimated that worldwide conventional crude oil production will peak in 2014, years earlier than anticipated. The scientists also showed that the world"s oil reserves are being reduced at a rate of 2.1 percent a year. The new model could help inform energy-related decisions and public policy debate, they suggest.