单选题Hitchhiking(搭车旅游) When I was in my teens(十几岁) and 20s, hitchhiking was a main form of long-distance transport. The kindness or curiosity of strangers (51) me all over Europe, North America, Asia and southern Africa. Some of the lift-givers became friends, many provided hospitality (52) the road. Not only did you find out much more about a country than (53) traveling by train or plane, but also there was that element of excitement about where you would finish up that night. Hitchhiking featured importantly in Western culture. It has books and songs about it. So what has happened to (54) ? A few years ago, I asked the same question about hitchhiking in a column on a newspaper. (55) of people from all over the world responded with their view on the state of hitchhiking. "If there is a hitchhiker's (56) it must be lran," came one reply. Rural Ireland was recommended as a friendly place for hitchhiking, (57) was Quebec, Canada. "if you don't mind being berated(严厉指责) for not speaking French. " But while hitchhiking was clearly still alive and well in many parts of the world, the (58) feeling was that throughout much of the west it was doomed(消亡). With so much news about crime in the media, people assumed that anyone on the open road without the money for even a bus ticket must present a danger. But do we (59) to be so wary both to hitchhike and to give a lift? In Poland in the 1960s, (60) a Polish woman who e-m/filed me, "the authorities introduced the Hitchhiker's Booklet. The booklet contained coupons for drivers, so each time a driver (61) somebody, he or she received a coupon. At the end of the season, (62) who had picked up the most hikers were rewarded with various prizes. Everybody was hitchhiking then. " Surely this is a good idea for society. Hitchhiking would increase respect by breaking down (63) between strangers. It would help fight (64) warming by cutting down on fuel consumption as hitchhikers would be using existing fuels. It would also improve educational standards by delivering instant (65) in geography, history, politics and sociology.

单选题 第三篇 Unpredictable Earthquake Humans are forever forgetting that they can't control nature. Exactly 20 years ago, a Time magazine cover story announced that "scientists are on the verge of being able to predict the time, place and even the size of earthquakes." The people of quake-ravaged (被地震破坏的) Kobe learned last week how wrong that assertion was. None of the methods conceived two decades ago has yet to discover a uniform wanting signal that preceded all quakes, let alone any sign that would tell whether the coming temblor (地震) is mild or a killer. Earthquake formation can be triggered by many factors, says Hiroo Kanamori, a seismologist (地震学家) at the California Institute of Technology. So, finding one all-purpose warning sign is impossible. One reason: Quakes tart deep in the earth, so scientists can't study them directly. If a quake precursor were found, it would still be impossible to ward humans in advance of all dangerous quakes. Places like Japan and California are riddle with hundreds, if not thousands, of minor faults. Prediction would be less important if scientists could easily build structures to withstand tremors. While seismic engineering has improved dramatically in the past 10 to 15 years, every new quake reveals unexpected weakness in "quake-resistant" structures, says Terry Tullis, a geophysicist at Brown University. In Kobe, for example, a highway that opened only last year was damaged. In the Northridge earthquake, on the other hand, well-built structures generally did not collapse. A recent report in Science adds yet more anxiety about life on the faulty lines. Researchers Fan computer simulations to see how quake resistant buildings would fall in a moderate size temblor, taking into account that much of a quake's energy travels in a large "pulse" of focused shaking. The results: both steel-frame buildings and buildings that sit on insulating rubber pads suffered severe damage. More research will help experts design stronger structures and possibly find quake precursors. But it is still a certainty that the next earthquake will prove once again that every fault cannot be monitored and every highway cannot be completely quake-proofed.

单选题A system to stop ships sinking A new computer system has been designed to stop ships sinking. The greatest danger to a holed vessel is that flooding of its compartments will make the (51) unstable enough to capsize. It is estimated that nearly half the ship (52) during the Second World War capsized because of loss of (53) . Pacer System of Burlington, Massachusetts has now refined a system devised by a reserve U.S. Navy officer, Stephen Drabouski. The computer is programmed with every possible eventuality of flood damage. Once the actual damage is keyed into the computer the operator is told by the computer (54) the implications are—and what can be done to re-establish the vessel. Trials on the American aircraft carrier USS Midway have (55) that the re action time to damage can be cut to a fiftieth. An incident was simulated in which the ship was (56) by two Exocet missiles causing flooding to 30 (57) receipt of the flood damage information in the damage control centre to a full printout of damage, effects, (58) countermeasures and an assessment of the result of the countermeasures. In a re-run of the incident (59) the computer program the damage control officer took four and a quarter hours to establish the effects, of the damage and another four hours (60) a decision could be taken on countermeasures. Although the system can be used to provide (61) control officers with advice, they do not, of course, have to (62) the information. Quite often the " (63) solution" will be unacceptable for operational reasons. When that happens the system can be asked for alternatives or the operator (64) interrogate the computer to find out what would happen if the officer's (65) solution was put into action.

单选题I was thoroughly confused about your answer. A. seldom B. quickly C. completely D. awfully

单选题Norman Blamey is an artist of deep convictions .

单选题These are our motives for doing it.

单选题The high-speed trains can have a major impact on travel preferences.

单选题Nuclear power, with all its inherent problems, is still the only {{U}}option{{/U}} to guarantee enoughenergy in the future. A. solution B. policy C. choice D. reason

单选题The use of the chemical may present a certain hazard to the laboratory workers

单选题{{B}}第三篇{{/B}} {{B}}Snowflakes{{/B}} You've probably heard that no two snowflakes are alike. Of course, nobody has ever confirmed that statement by examining every one of the estimated one septillion snowflakes that drift to Earth each year. Still, Kenneth Libbrecht, a professor at the California Institute of Technology, is confident that the statement is true. Snowflakes aren't flaky, says Libbrecht. At their basic level, they're crystalline. The lattice of every snowflake is six-sided in shape. The simplest snow crystals are six-sided flat plates and six-sided columns. Such crystals are common in places where the air is extremely cold and dry. Snow crystals acquire their special beauty when their simple six-sided symmetry blossoms. Under the right conditions, each of the six comers of a crystal sprouts what is called an arm. In a matter of minutes, the arms can become highly ornate and give the crystal a star like appearance. Several factors in the environment affect the shape and growth rate of a snow crystal. One factor is humidity. Crystals grow faster and in more intricate shape as humidity increases. A second factor is air temperature. A snowflake is born when several molecules of water vapor in a cloud land on a speck of dust and freeze to form a simple crystal. As the young crystal bops around in the cloud, it passes through air pockets of varying temperatures. If the crystal passes through a pocket of air that is, say, -15 degrees Celsius, it will grow quickly and sprout six arms, says Libbrecht. If the crystal is then tossed into a warmer pocket, one about -10℃, the arms' tips will stop growing quickly and form six-sided plates. If the crystal then drifts into an even warmer pocket of about -5℃, its top and bottom will grow more quickly than its sides and become more column like in shape. In the course of its life span, a snow-crystal might flutter through many warmer and colder pockets, acquiring a complicated and unique growth history. Such a history will give rise to a snowflake that is unlike any other. Each arm on the snowflake will look exactly like every other one, but the crystal itself will be one of a kind. Using his cooling tanks, Libbrecht has learned how to create snow crystals of different shapes--plates, columns, needles, etc. Libbrecht has even refined his techniques so that he can make crystals that look highly similar to one another. Still, he lacks the control to manufacture identical twin snowflakes. A slight difference in humidity and temperature can upset the growth profile6 of a crystal.

单选题I remember lots of things.

单选题The League of Women Voters is a nonpartisan organization that promotes {{U}}informed{{/U}} active public participation in government.

单选题He proposed to her but she {{U}}turned{{/U}} him {{U}}down{{/U}}.

单选题Should English classes be compulsory at the elementary or primary school level in countries where it is not the native language?

单选题Sorry I didn't turn up—I {{U}}completely{{/U}} forgot.

单选题More than one-third of the Chinese in the United States live in California, predominantly in San Francisco.

单选题According to the passage, a volcano sends out

单选题It was a fascinating painting, with clever use of color and light.

单选题 Crystal Ear One day a friend asked my wife Jill if I wanted a hearing aid. "He certainly does," replied Jill. After hearing about a remarkable new product, Jill finally got up the nerve to ask me if I'd ever thought about getting a hearing aid. "No way," I said. "It would make me look 20 years older." "No, no," she replied. "This is entirely different. It's Crystal Ear!" Jill was right. Crystal Ear is different—not the old-styled body worn or over-the-ear aid, but an advanced personal sound system so small that it's like contacts (隐形眼镜) for your ears. And Crystal Ear is super-sensitive and powerful, too. You will hear sounds your ears have been missing for years. Crystal Ear will make speech louder, and the sound is pure and natural. I couldn't believe how tiny it is. It is smaller than the tip of my little finger and it's almost invisible when worn. There are no wires, no behind-the-ear device. Put it in your ear and its ready-to-wear mold (形状) fits comfortably. Since it's not too loud or too tight, you may even forget that you're wearing it! Use it at work or at play. And if your hearing problem is worse in certain situations, use Crystal Ear only when you need it. Hearing loss, which occurs typically prior to teenage years, progresses throughout one's lifetime. Although hearing loss is now the world's number one health problem, nearly 90 percent of people suffering hearing loss choose to leave the problem untreated. For many millions, treating hearing loss in a conventional way can involve numerous office visits, expensive testing and adjustments to fit your ear. Thanks to Crystal Ear, the "sound solution" is now convenient. Almost 90 percent of people with mild hearing loss, and millions more with just a little hearing drop-off (下降), can be dramatically helped with Crystal Ear. More over, its superior design is energy-efficient, so batteries can last months. Crystal Ear is now available to help these people treat their hearing loss with a small hearing amplifier (放大器).

单选题This custom is still prevailing among members of the older generation.