单选题Marsha confessed that she knew nothing of computer.A. reportedB. admittedC. hopedD. answered

单选题The soldier displayed remarkable courage in the battle.

单选题In temperate regions the growth rings on turtles’ epidermal plates reflect seasonal variations in growth. A. indicate B. stimulate C. include D. prevent

单选题Cell Phones Increase Traffic, Pedestrian Fatalities Cell phones are a danger on the road in more ways than one. Two new studies show that talking on the phone while traveling, whether you're driving or on foot is increasing both pedestrian deaths and those of drivers and passengers, and recommend crackdowns on cell use by both pedestrians and drivers. The new studies, lead-authored by Rutgers University, Newark, Economics Professor Peter D Loeb, relate the impact of cell phones on accident fatalities to the number of cell phones in use, showing that the current increase in deaths resulting from cell phone use follows a period when cell phones actually helped to reduce pedestrian and traffic fatalities. However, this reduction in fatalities disappeared once the numbers of phones in use reached a "critical mass" of 100 million, the study found. These studies looked at cell phone use and motor vehicle accidents from 1975 through 2002, and factored in a number of variables, including vehicle speed, alcohol consumption, seat belt use, and miles driven. The studies found the cell phone-fatality correlation to be true even when including factors such as speed, alcohol consumption, and seat belt use. Loeb and his co-author determined that, at the current time, cell phone use has a "significant adverse effect on pedestrian safety" and that "cell phones and their usage above a critical thresholds adds to motor vehicle fatalities." In the late 1980s and part of the 1990s, before the numbers of phones exploded, cell phone use actually had a "life-saving effect" in pedestrian and traffic accidents, Loeb notes. "Cell-phone users' were able to quickly call for medical assistance when involved in an accident. This quick medical response actually reduced the number of traffic deaths for a time," Loeb hypothesizes. However, this was not the case when cells were first used in the mid-1980s, when they caused a "life-taking effect" among pedestrians, drivers and passengers in vehicles. In those early days, when there were fewer than a million phones, fatalities increased, says Loeb, because drivers and pedestrians probably were still adjusting to the novelty of using them, and there weren't enough cell phones in use to make a difference in summoning help following an accident, he explains. The "life-saving effect" occurred as the volume of phones grew into the early 1990s, and increasing numbers of cells were used to call 911 following accidents, leading to a drop in fatalities, explains Loeb. But this life-saving effect was canceled out once the numbers of phones reached a "critical mass" of about 100 million and the "life-taking effect" increased accidents and fatalities outweighed the benefits of quick access to 911 services, according to Loeb. Loeb and his co-authors used econometric models to analyze data from a number of government and private studies. He and his co-authors recommend that governments consider more aggressive policies to reduce cell phone use by both drivers and pedestrians, to reduce the number of fatalities.

单选题The robotic technology for surgeries on people has brought a handsome profit to Medrobotics.

单选题{{B}}第二篇{{/B}} Certainly no creature in the sea is odder than the common sea cucumber(海参). All living creatures, especially human beings, have their peculiarities, but everything about the little sea cucumber seems unusual. What else can be said about an odd animal that, among other eccentricities, eats mud, feeds almost continuously day and night but can live without eating for long periods, and can be poisonous hut is considered supremely edible by gourmets(美食家) ? For some fifty million years, despite all its eccentricities, the sea cucumber has subsisted on its diet of mud. It is adaptable enough to live attached to rocks by its tube feet, under rocks in shallow water, or on the surface of mud fiats. Common in cool water on both Atlantic and Pacific shores, it has the ability to suck up .mud or sand and digest whatever nutrients are present. Sea cucumbers come in a variety of colors, ranging from black to reddish-brown to sandcolor and nearly white. One form even had vivid purple tentacles. Usually the creatures are cucumbers-shaped——hence their name——and because they are typically rock inhabitants, this shape, combined with flexibility, enables them to squeeze into narrow cracks where they are safe from predators and ocean currents. Although they have voracious appetites, eating day and night, sea cucumbers have the capacity to become inactive and live at a low metabolic rate feeding sparingly or not at all for long periods, so that the marine organisms that provide their food have a chance to multiply. If it were not for this faculty, they would devour all the food available in a short time and would probably starve themselves out' of existence. But the most spectacular thing about the sea cucumber is the way it defends itself. Its major enemies are fish and crabs, when attacked, it squirts all its internal organs into the water. It also casts off attached structures such as tentacles. The sea cucumber will eviscerate排除内脏) and regenerate itself if it is attacked or even touched; it will do the same if the surrounding water temperature is too high or if the water becomes too polluted.

单选题As soon as we crossed the border, enemy troops started firing at our troops.A. shootingB. fightingC. strikingD. hitting

单选题By the way, if you are wondering where the Bluetooth name originally carne from, it is named after a Danish Viking and King, Harald Blaatand (translated as Bluetooth in Englishl. who lived in the latter part of the 10[th] century. Harald Blaatand united and controlled Denmark and Norway (hence the inspiration on the name: uniting devices through Bluetooth). He got his name from his very dark hair which was unusual for Vikings, Blaatand means dark complexion. However, a more popular, ( but less likely reason) , was that Old Harald had an inclination towards eating Blueberries ,so much so his teeth became stained with the color, leaving Harald with a unique set of molars (白齿). Who was Harald Blaatand?A. A Viking pirate in the 10[th] century.B. The king of Denmark for most part of the 10[th] century.C. The king ruling Denmark for the latter part of the 10th century.D. A typical Viking who had very dark hair.

单选题That player is {{U}}eternally{{/U}} arguing with the referee

单选题The conclusion can be deduced from the premises.

单选题You can tell from the yellow streaks on the leaves that the plant has been infected. A. signs B. marks C. layers D. spots

单选题 What Is the Coolest Gas in the Universe What is the coldest air temperature ever recorded on the Earth? Where was this low temperature recorded? The coldest recorded temperature on Earth was -91℃, which {{U}} {{U}} 1 {{/U}} {{/U}}in Antarctica in 1983. We encounter an interesting situation when we discuss temperatures in {{U}} {{U}} 2 {{/U}} {{/U}}temperatures in Earth orbit actually range from about 20℃ to 120℃. The temperature depends upon {{U}} {{U}} 3 {{/U}} {{/U}}you are in direct sunlight or shade. Obviously, -120℃ is colder than our body can safely endure. Thank NASA science for well-designed space {{U}} {{U}} 4 {{/U}} {{/U}}that protect astronauts from these temperature extremes. The space temperatures just discussed affect only our areal of the solar {{U}} {{U}} 5 {{/U}} {{/U}}. Obviously, it is hotter closer to the Sun and colder as we travel away from the Sun. Astronomers estimate temperatures at Pluto are about -210℃. How cold is the lowest estimated temperature in the entire universe? Again, it depends upon your {{U}} {{U}} 6 {{/U}} {{/U}}. We are taught it is supposedly {{U}} {{U}} 7 {{/U}} {{/U}}to have a temperature below absolute zero, which is -273℃, at which atoms do not move. Two scientists, whose names are Cornell and Wieman, have successfully cooled down a gas to a temperature barely {{U}} {{U}} 8 {{/U}} {{/U}}absolute zero. They won a Nobel Prize in Physics in 2001 for their work—not a discovery, in this case2. Why is the two scientists work so important to science? In the 1920s, Satyendra Nath Bose was studying an interesting {{U}} {{U}} 9 {{/U}} {{/U}}about special light particles we now call photons. Bose had trouble {{U}} {{U}} 10 {{/U}} {{/U}}other scientists to believe his theory, {{U}} {{U}} 11 {{/U}} {{/U}}he contacted Albert Einstein. Einstein's calculations helped him, theorize that atoms {{U}} {{U}} 12 {{/U}} {{/U}}behave as Bose thought—but only at very cold temperatures. Scientists have also discovered that {{U}} {{U}} 13 {{/U}} {{/U}}atoms can help them make the world's atomic docks even more accurate. These clocks are so accurate today they would only lose one second {{U}} {{U}} 14 {{/U}} {{/U}}six million years! Such accuracy will help us travel in space because distance is velocity times time (d=v×t). With the long distances involved in space {{U}} {{U}} 15 {{/U}} {{/U}}, we need to know time as accurately as possible to get accurate distance.

单选题Sino-Japan Animosity Lessens Chinese and Japanese people view each other slightly more positively than last year, according to a survey released on Wednesday at a press conference in Beijing. The survey is jointly sponsored by China Daily and Genron NPO, a Japanese think tank similar to the American Council on Foreign Relations. It also found overwhelming agreement in both countries that Sino-Japanese relations were important. The survey is a part of the Beijing-Tokyo Forum, an annual gathering of senior government officials and representatives from Chinese and Japanese NGOs designed to improve communication and understanding between the two countries. Conducted every year for five years now, the survey focused on two different groups of people: ordinary citizens, and intellectuals. In China, the intellectual group was comprised mainly of university students from well-known schools like Peking University. In Japan, the "intellectual" group was mainly made up of previous members of Genron NPO. Among ordinary Chinese polled, 35.7 percent said they have "very good" or "relatively good" impressions of Japan, a 5.5-percentage-point increase compared with last year. 45.2 percent of Chinese students had a positive impression of Japan, two percentage points more than last year. Only 26.6 percent of Japanese have a positive impression of China, however. Still, an overwhelming majority of the respondents from each country said Sino-Japanese relations were "important" and wanted their leaders to deepen talks and cooperation with each other. But 51.9 percent of ordinary people and 42.4 percent of students in China said they saw no change in relations between the two countries over the last year. In Japan, 64.8 percent of those ordinary people and 53.4 percent of intellectuals surveyed shared the view that there was no improvement in bilateral ties this year. Historical issues and territorial disputes remain two major obstacles to improving bilateral relations, the survey found. What concerns the Chinese most are historical issues, visits by Japanese officials to Yasukuni Shrine, and the Nanjing Massacre. Perceptions on economic and trade relations have improved, though. About 47 percent of ordinary Japanese said China had been "helpful" this year in fighting the global economic crisis, compared with just 30 percent last year. The percent of Japanese intellectuals who said Chinese economic growth was good for Japan increased from 65.8 percent to 81.4 percent this year. Cooperation in East Asian issues, trade and investment, energy, and the environment and climate change top the list of common concerns that people in China and Japan want their leaders to talk about in bilateral meetings, the survey found. Civil exchanges were regarded by the most people from the both countries as an important way to improve relations. 90.7 percent of the students and 85.7 percent of the ordinary people in China and 95.8% of intellectuals and 74.8% of the ordinary people in Japan viewed civil exchanges as "important" or "relatively important". Chinese and Japanese both learn about each other"s countries mostly through television news and newspapers, the survey found.

单选题It is no use debating the relative merits of this policy.

单选题He paused, waiting for her to {{U}}digest{{/U}} the information. A. withhold B. exchange C. understand D. contact

单选题Electric Backpack Backpacks are convenient. They can hold your books, your lunch, and a change of clothes, leaving your hands free to do other things. Someday, if you don"t mind carrying a heavy load, your backpacks might also power your MP3 player, keep your cell phone running, and maybe even light your way home. Lawrence C. Rome and his colleagues from the University of Pennsylvania in Philadelphia and the Marine Biological Laboratory in WoodsHole, have invented a backpack that makes electricity from energy produced while its wearer walks. In military actions, search-and-rescue operations, and scientific field studies, people rely increasingly on cell phones, global positioning system (GPS) receivers, night-vision goggles, and other battery powered devices to get around and do their work. The backpack"s electricity-generating feature could dramatically reduce the amount of a wearer"s load now devoted to spare batteries, report Rome and his colleagues in the Sept. 9. The backpack"s electricity-creating powers depend on springs used to hang a cloth pack from its metal frame. The frame sits against the wearer"s back, and the whole pack moves up and down as the person walks. A gear mechanism converts vertical movements of the pack to rotary motions of an electrical generator, producing up to 7.4 watts. Unexpectedly, tests showed that wearers of the new backpack alter their gaits in response to the pack"s oscillations, so that they carry loads more comfortably and with less effort than they do ordinary backpacks. Because of that surprising advantage, Rome plans to commercialize both electric and non-electric versions of the backpack. The backpack could be especially useful for soldiers, scientists, mountaineers, and emergency workers who typically carry heavy backpacks. For the rest of us, power-generating backpacks could make it possible to walk, play video games, watch TV, and listen to music, all at the same time. Electricity-generating packs aren"t on the market yet, but if you do get one eventually, just make sure to look both ways before crossing the street!

单选题It is said that the house along the street will be demolished.A. pulled downB. rebuiltC. renovatedD. constructed

单选题We explored the possibility of closer trade links at the conference. A. rejected B. investigated C. proposed D. postponed

单选题Although it is not our normal practice to give credit, this time I think we should consider the matter more closely.