单选题The very north and south Uregions/U are covered with ice and snow.

单选题It hard for the young people to imagine what Usevere/U conditions their parents .once lived uder.

单选题The once barren hillsides are now good farmland.

单选题The writer suggests that you go to see a doctor when you feel you are losing your voice.

单选题Google's Gmail system, which serves millions of customers around the world, shut down yesterday. The problem may hurt its efforts to market applications which include e—mail to businesses. Google prides itself on the reliability of its software, at least according to its marketing pitch. It is not clear why Google had the problem. It keeps thousands of servers. Some of those may have developed trouble or some outside programmer, a hackea may have sent a bug into the system to make it collapse. What happened to Google yesterday?A. It lost millions of customers.B. Its Gmail system collapsed.C. Its market application program failed.D. Its servers were destroyed by hackers.

单选题What {{U}}puzzles{{/U}} me is why his books are so popular. A. confuses B. shocks C. influences D. concerns

单选题Traffic is bad, particularly in the city center.

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

单选题Learning Disabilities Learning disabilities are very common. They affect perhaps 10 percent of all children. Four times as many boys as girls have learning disabilities. Since about 1970, new research has helped brain scientists understand these problems better. Scientists now know there are many different kinds of learning disabilities and that they are caused by many different things. There is no longer any question that all learning disabilities result from differences in the way the brain is organized. You cannot look at a child and tell if he or she has a learning disability. There is no outward sign of the disorder. So some researchers began looking at the brain itself to learn what might be wrong. In one study, researchers examined the brain of a learning-disabled person who had died in an accident. They found two unusual things. One involved cells in the left side of the brain, which control language. These cells normally are white. In the learning disabled person, however, these cells were gray. The researchers also found that many of the nerve cells were not in a line the way they should have been. The nerve cells were mixed together. The study was carried out under the guidance of Norman Geschwind, an early expert on learning disabilities. Doctor Geschwind proposed that learning disabilities resulted mainly from problems in the left side of the brain. He believed this side of the brain failed to develop normally. Probably, he said, nerve ceils there did not connect as they should. So the brain was like an electrical device in which the wires were crossed. Other researchers did not examine brain tissue. Instead, they measured the brain"s electrical activity and made a map of the electrical signals. Frank Dully experimented with this technique at Children"s Hospital Medical Center in Boston. Doctor Dully found large differences in the brain activity of normal children and those with reading problems. The differences appeared throughout the brain. Doctor Dully said his research is evidence that disabilities involve damage to a wide area of the brain, not just the left side.

单选题The river widens considerably as it begins to turn west.

单选题What percentage of the earth's water can man actually use at present?

单选题Living Standards Around the World The differences in living standards around the world are vast. In 1993, the average American had an income of about $25,000. In the same year, the average Mexican earned $7,000, and the average Nigerian earned $1,500. Not surprisingly, this large variation in average income is reflected in various measures of the quality of life. Changes in living standards over time are also large. In the United States, incomes have historically grown about 2 percent per year (after adjusting for changes in the cost of living). At this rate, average income doubles every 35 years. In some countries, economic growth has been even more rapid. In Japan, for instance, average income has doubled in the past 20 years, and in South Korea it has doubled in the past 10 years. What explains these large differences in living standards among countries and over time? The answer is surprisingly simple. Almost all variation in living standards is attributable to differences in countries' productivity—that is, the amount of goods and services produced from each hour of a worker's time. In nations where workers can produce a large quantity of goods and services per unit of time, most people enjoy a high standard of living; in nations where workers are less productive, most people must endure a more meager existence. Similarly, the growth rate of a nation's productivity determines the growth rate of its average income. The fundamental relationship between productivity and living standards is simple, but its implications are far-reaching. If productivity is the primary determinant of living standards, other explanations must be of secondary importance. For example, people might think that labor unions or minimum-wage laws contributed to the rise in living standards of American workers over the past century. Yet the real hero of American workers is their rising productivity. The relationship between productivity and living standards also has great implications for public policy. When thinking about how any policy will affect living standards, the key question is how it will affect our ability to produce goods and services. To improve living standards, policymakers need to raise productivity by ensuring that workers are well educated, have the tools needed to produce goods and services, and have access to the best available technology.

单选题I have extreme sense of happiness at this moment.A. hopeB. wishC. feelingD. dream

单选题Haute Tech In recent years, backpacks have begun sporting outside pockets that are, not coincidentally, the perfect size for an iPod. Handbags routinely feature cell-phone compartments. And now, from practical to modem, the fashion industry is taking a cue from these gadgets, integrating their technologies into the fabrics rather than merely providing storage for them. Known as "haute(高级定做服装) tech." these designs sometimes resemble costumes borrowed from the set of a sci-fi thriller. Like all old mood ring, one dress can sense the mood of its wearer by gauging his or her gestures and then respond with all appropriate song from its MP3-integrated hood (风帽, 兜帽). The innovations know no bounds, and can be quite funny: Erik De Nijs, a student at the Utrecht School of the Arts in the Netherlands, created a pair of tech jeans that incorporates a wireless Bluetooth keyboard into the lap of the pants. Speakers are integrated into the knees of the jeans and a mouse is conveniently stored in the hack pocket. While some might find this kind of lap typing mildly valgar, it highlights the way haute tech is pushing practical, wearable technology. Other garments use a nickel-anti-titanium (镍和钛) shape-memory alloy to move shinning panels of fabric as if they are breathing, like coral (珊瑚) shifting with the title. " Clothing becomes the interface to tell a story, "says British haute tech designer DiMainstone, au artist in residence at New York's Eyebeam studio. One of Mainstone's newest projects, Sharewear, stems from the idea thin in today's fast-paced society, time for" intimate bomey encounters" is limited. So Mainstone created a costume made up of modules inspired by icons of the home, like the armrest of a favorite sofa. In addition to looking cool, Sharewear is meant to evoke the idea that clothing serves both to shelter and to define us—just like our homes. "I wanted that esthetic of something that was very familiar." Mainstone says. Widely credited as the founder of haute tech, British designer Hussein Chalayan-twice named British designer of the year-is the subject of a fun and fascinating new exhibit at the London Design Museum called "From Fashion and Back" (through May 17), which highlights his 15-year career. Among the items on display: a garment made of crystals and 200 moving lasers to create a living light show, and two LED—screen video dresses that illuminate underwater sea life. Chalayan believes that integrating technology with fashion is "the only way in the world to create something new," he says. "These are the prototypes for things to. come. They need this investment. /

单选题Bladder wrack, a tough, leathery brown seaweed, {{U}}clings to{{/U}} rocks tenaciously.

单选题Computers in Cars You"re far from home on a lonely road. Shadowy forests stretch away on both sides. A thick mist (雾) makes it difficult to see far beyond your car"s windshield (挡风玻璃). "Can this be route 90A?" you wonder. If it is, you should be near a town. Yet there"s no hint of one. Night is closing in. And you"re low on gasoline. This is a situation where an in-car computer that can navigate would be a big help. A car computer that navigates? Yes! Such computers exist. Several experimental models are being tested by General Motors, Ford, Chrysler, and several foreign car makers. These computers vary in detail. But they all contain series of maps on videodiscs or videotapes. For example, one computer system contains 13,300 maps covering the continental US. Before starting out on a trip, a driver can type in the code for the region he or she plans to drive through. The computer then shows a map of that region. At the same time, a tiny radio receiver linked to the computer goes to work. It picks up signals from navigation satellites such as the NAVSTAR network. Using these signals, the computer shows the car"s position at all times and displays this position on the map. The computer can also calculate and display the best route to follow. A navigation computer may also receive and use data about road construction, weather conditions, and traffic jams. This information would be displayed to the driver and the computer would also use the information to work out alternate (交替的) routes. Most cars nowadays also contain computers that help cars run more efficiently. Microprocessors (微处理机) control certain engine functions by regulating the mixing of fuel. Data on car speed, oil pressure, revolutions per minute, engine temperature, and fuel level can be displayed as digital data (numbers) or warning lights. Some auto designers suggest that a central computer display be used to clearly present such timely information as car speed and fuel level. Warning lights would indicate a drop in oil pressure or a sudden rise in engine temperature. To get more information on these conditions, the driver could call it up on the computer display screen. When needed, the computer could be "asked" to provide navigation aid or information about the car"s condition.

单选题 下面有3篇短文，每篇短文后有5道小题。请根据短文内容，为每题确定1个最佳选项。{{B}}第一篇{{/B}} Crop Problem Advances in technology have helped more of the world's population live better and longer, and that is part of our problem[ Better health standards have kept larger number of people alive. The world's population is now almost four billion and expected to double in 25 years. Growing population and slowly rising living standards have increased our need for food at the rate of 30 million tons per year. As a result, the world's stockpile of food(食物储备) is declining by about 10 million tons per year. From the early 1950s until 1972 ,world food production increased greatly. The Green Revolution (绿色革命) extended scientific techniques to agriculture in the form of hybrid seed (杂交种)and poultry (禽类), chemical fertilizers (化学肥料) and pesticides (杀虫剂), and complex irrigation systems. Strains (品种) of corn (玉米), sorghum (高粱), soybeans (大豆), wheat and rice were developed to flourish under particular climate and soil conditions. In the United States, corn production rose to 110 bushels(蒲式耳：谷物、水果、蔬菜等容量单位，在英国相当于36,368升，在美国相当于35,238升) per acre from only 26 bushels per acre in the early 1900s. Milk production rose to 10,000 pounds per cow per year, compared with 600 in India. Chickens were bred to eat less, grow to maturity in shorter time, and produce more eggs. As a result of such scientific advances, our twelve midwestern states alone now feed one fourth of the world's people. Crop disaster in 1972 brought an apparent end to the growth in production. Much of the extra yields had come from the use of chemical fertilizers, primarily petroleum based and now in short supply. The drop in world supplies of petroleum-based fertilizers is expected to cause a drop in crop yields of ten tons for each one ton decline in fertilizers applied. This presents a particular problem for underdeveloped nations that often lack the foreign exchange necessary for buying fertilizer. The problem is so severe that Philip Handier, president of the National Academy of Sciences, has predicted one million child deaths per month in these nations by the year 2025.

单选题Everyone aboard the plane perished in the air crash.A. survivedB. disappearedC. diedD. left

单选题If headaches only occur at night, lack of fresh air is often the cause.

单选题The policeman stopped him when he was driving home and accused him of speeding.