单选题Since the energy crisis, these big cars have become a real {{U}}liability{{/U}}. They cost too much to run.

单选题According to the text, the most important thing for the futurists to grasp is

单选题[此试题无题干]

单选题But if you place your order not later than the end of this month, we would ______ prompt shipment． A．sure B．assure C．insure D．ensure

单选题Now and in the future, we will live as free people, not in fear and never at the mercy of any foreign powers.

单选题I believe reserves of coal here ______ to last for fifty years.

单选题If you go by ______ train ,you can have quite a comfortable journey ,but make sure you get ______ fast one.A. /; /B. /; aC. the; aD. /;/

单选题Vitamins are organic compounds necessary in small amounts in the diet for the normal growth and maintenance of life o animals, including man. They do not provide energy, (61) do they construct or build any part of the body. They are needed for (62) foods into energy and body maintenance. There are thirteen or more of them, and if (63) is missing a deficiency disease becomes (64) . Vitamins are similar because they are (65) of the same elements--usually carbon, hydrogen, oxygen, and (66) nitrogen. They are different (67) their elements are arranged (68) , and each vitamin (69) one or more specific (70) in the body. (71) enough vitamins is essential to life, (72) the body has no nutritional use for (73) vitamins. Many people, (74) , believe in being on the "safe side" and thus take extra vitamins. However, a (75) diet will usually meet all the body's vitamin needs.

单选题 阅读下列短文，然后根据短文的内容从每小题的四个选择项中，选出最佳的一项。{{B}}A{{/B}} Our house was the oldest in the village. It was nearly three hundred years old. Although we were six children, and a mother and a father, we were not by any means alone in the house. We were sharing it with big families of mice and spiders(蜘蛛). There were great- grandparents, grandparents, fathers and mothers, and hundreds of mouse and spider children. My mother would never let us kill a spider, not even a hairy old grandfather. "If you want to live and rich," she used to say, "let a spider run alive." And so the spiders, our enemies, were beaten and kicked but never killed. But she had no such dealing with the mice. One of our problems was that my mother hated cats; and we never owned a single cat. We kept dogs, often two or three at the same time, but very few dogs can move fast enough to catch a lively young mouse. Every night we set a dozen mousetraps(捕鼠器), each with a small piece of cheese. Sometimes the cheese disappeared, but the mice usually seemed too wise to go near the traps. We seldom caught anything. My mother herself had far better luck. Her arms and hands moved as fast as any cat's paws. Often, when she was scrubbing or polishing a floor on her hands and knees, some foolish little grey fellow would try to run past her. He never got very far. Quick as lightning her hard hands would smack(用掌击) together--and there on the floor would be one dead mouse. "Oh, you were a proud one," she would say to it then. One day my father decided to clean out the water tank, which stood on four iron legs in a corner upstairs. He was soon sorry that he had started the job. In the mud at the bottom of the tank, there were sixteen of the little grey fellows, all as solid and hard as stones. We had been drinking the water from that tank for twelve years.

单选题The performance of the English Team was very ______. They played much worse than expected.

单选题The plane ______ at 7: 00 p. m., so I have to be at the airport by 6 : 40 at the latest.A. has leftB. is to leaveC. will have leftD. leaves

单选题Buffett distinguishes himself for ______.

单选题 Languages are remarkably complex and wonderfully complicated organs of culture. They contain the quickest and the most efficient means of communicating within their respective culture. To learn a foreign language is to learn another culture. In the words of a poet and philosopher, "As many languages as one speaks, so many lives one lives. " A culture and its language are as necessary as brain and body; while one is a part of the oth- er, neither can function without the other. In learning a foreign language, the best begin- ning would be starting with the non-language elements of the language: its gestures, its body language, etc. Eye contact is extremely important in English. Direct eye contact leads to understanding, or, as the English saying goes, seeing eye-to-eye. We can never see eye-to-eye with a native speaker of English until we have learned to look directly into his eyes.

单选题"How long have you worked on the farm?" "( )the end of last year.

单选题From this passage we know that _________.

单选题{{B}}Text 2{{/B}} Swimmers can drown in busy swimming pools when lifeguards fail to notice that they are in trouble. The Royal Society for the Prevention of Accidents says that on average 15 people drown in British pools each year, but many more suffer major injury after getting into difficulties. Now a French company has developed an artificial intelligence system called Poseidon that sounds the alarm when it sees someone in danger of drowning. When a swimmer sinks towards the bottom of the pool, the new system sends an alarm signal to a poolside monitoring station and a lifeguard's pager. In trials at a pool in Ancenis, near Nantes, it saved a life within just a few months, says Alistair McQuade, a spokesman for its manufacturer, Poseidon Technologies. Poseidon keeps watch through a network of underwater and overhead video cameras. AI software analyses the images to work out swimmers, trajectories. To do this reliably, it has to tell the difference between a swimmer and the shadow of someone being cast onto the bottom or side of the pool. "The underwater environment is a very dynamic one, with many shadows and reflections dancing around." Says McQuade. The software does this by "projecting" a shape in its field of view onto an image on the far wall of the pool. It does the same with an image from another camera viewing the shape from a different angle. If the two projections are in the same position, the shape is identified as a shadow and is ignored. But if they are different, the shape is a swimmer and so the system follows its trajectory. To pick out potential drowning victims, anyone in the water who starts to descend slowly is added to the software's "pre-alert" list, says McQuade. Swimmers who then stay immobile on the pool bottom for 5 seconds or more are considered in danger of drowning. Poseidon double-checks that the image really is of a swimmer, not a shadow, by seeing whether it obscures the pool's floor texture when viewed from overhead. If so, it alerts the lifeguard, showing the swimmer's location on a poolside screen. The first full-scale Poseid6n system will be officially opened next week at a pool in High Wycombe, Buckinghamshire. One man who is impressed with the idea is Travor Baylis, inventor of the clockwork radio. Baylis runs a company that installs swimming pools—and he was once an underwater escapologist with a circus. "I say full marks to them if this works and can save lives," he says. But he adds that any local authority spending ￡30,000— plus on a Poseidon system ought to be investing similar amounts in teaching children to swim.

单选题It is said that in England death is pressing, in Canada inevitable and in California optional. Small wonder. Americans" life expectancy has nearly doubled over the past century. Failing hips can be replaced, clinical depression controlled, cataracts removed in a 30-minute surgical procedure. Such advances offer the aging population a quality of life that was unimaginable when I entered medicine 50 years ago. But not even a great health-care system can cure death—and our failure to confront that reality now threatens this greatness of ours. Death is normal; we are genetically programmed to disintegrate and perish, even under ideal conditions. We all understand that at some level, yet as medical consumers we treat death as a problem to be solved. Shielded by third-party payers from the cost of our care, we demand everything that can possibly be done for us, even if it" s useless. The most obvious example is late-stage cancer care. Physicians frustrated by their inability to cure the disease and fearing loss of hope in the patient—too often offer aggressive treatment far beyond what is scientifically justified. In 1950, the U. S. spent 0.7 billion on health care. In 2002, the cost will be billion. Anyone can see this trend is unsustainable. Yet few seem willing to try to reverse it. Some scholars conclude that a government with finite resources should simply stop paying for medical care that sustains life beyond a certain age—say 83 or so. Former Colorado governor Richard Lamm has been quoted as saying that the old and infirm "have a duty to die and get out of the way" , so that younger, heallhier people can realize their potential. I would not go that far. Energetic people now routinely work through their 60s and beyond, and remain dazzlingly productive. At 78, Viacom chairman Sumner Redstone- jokingly claims to be 53. Supreme Court Justice Sandra Day O" Connor is in her 70s, and former surgeon general C. Everett Koop chairs an Internet start-up in his 80s. These leaders are living proof that prevention works and that we can manage the health problems that come naturally with age. As a mere 68-year-old, I wish to age as productively as they have. Yet there are limits to what a society can spend in this pursuit. As a physician, I know the most costly and dramatic measures may be ineffective and painful. I also know that people in Japan and Sweden, countries that spend far less on medical care, have achieved longer, healthier lives than we have. As a nation, we may be overfunding the quest for unlikely cures while underfunding research on humbler therapies that could improve people" s lives.