单选题The most crucial problem any economic system faces is how to use its scarce resources.

单选题Scott seized the opportunity to present his proposal to the director.

单选题It is anticipated that this contract will considerably increase sales over the next three years.A. apparentlyB. slightlyC. greatlyD. steadily

单选题Twitter, the micro-blogging service used by tens of millions of people, went off-line last month. It blamed the trouble on a malicious programmer in Russia who was trying to shut down the account of a user in neighboring Georgia. It is astonishing the local actions of a small number of programmers can bring an entire Internet service to its knees, but that appears to have been the case. Who was responsible for the collapse of Twitter?A. All its users.B. A malicious programmer in Russia.C. A small number of programmers.D. A user in neighboring Georgia,

单选题With immense relief I stopped running.

单选题The old concerns lose importance and some of them vanish altogether.

单选题At 80, Peck was still vigorous and living in Paris.A. happyB. aloneC. busyD. energetic

单选题Could you please tell me your standards when selecting a candidate?

单选题A new system of quality control was {{U}}brought{{/U}} in to overcome the defects in the firm's products. A. invested B. introduced C. installed D. insisted

单选题下面有3篇短文，每篇短文后有5道题。请根据短文内容，为每题确定1个最佳选项。{{B}}第一篇{{/B}} Pool Watch 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 MeQuade, a spokesman for its maker, Poseidon Technologies. Poseidon keeps watch through a network of underwater and overheard video cameras. AI software analyses the images to work out swimmers trajectories(轨道，轨线). 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 of 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 Poseidon 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 (表演脱身术的人)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 230,000 -- plus on a Poseidon system ought to be investing similar amounts in teaching children to swim.

单选题I had nothing to say regarding this matter.

单选题A notably short man, he plays basketball with his staff several times a week.

单选题What people often talk is their dream.A. worryB. showC. reduceD. mention

单选题He often finds fault with my work.A. criticizesB. praisesC. evaluatesD. talks about

单选题From my standpoint, this thing is just ridiculous. A．field B．point of view C．knowledge D．information

单选题 The Appearance of Woman Women, as all research suggests, are much more critical of their appearance than men—much less likely to admire what they see in the mirror. Up to 8 out of 10 women are dissatisfied with their reflection, and more than half may see a distorted image. Men looking in the mirror are more likely to be either pleased with what they see or indifferent. Research shows that men generally have a much more positive body image than women—if anything, they may tend to over-estimate their attractiveness. Some men looking in the mirror may literally not see the flaws in their appearance. Why are women so much more self-critical than men? Because women are judged on their appearance more than men, and standards of female beauty are considerably higher and more inflexible. Women are continually bombarded with images of the "ideal" face. And constant exposure to idealized images of female beauty on TV, magazines and billboards makes exceptional good looks seem normal and anything short of perfection seem abnormal and ugly. It has been estimated that young women now see more images of outstandingly beautiful women in one day than our mothers saw throughout their entire adolescence. Also, most women trying to achieve the impossible standards of female beauty have in fact become progressively more unrealistic during the last century. In 1917, the physically perfect woman was about 5 feet 4 inches tall and weighed nearly 10 stone (英石). Even 25 years ago, top models and beauty queens weighed only 8% less than the average women, now they weigh 23% less. The current media ideal for women is achievable by less than 5% of the female population—and that's just in terms of weight and size. If you want the ideal shape, face etc., it's probably more like 1%.

单选题Many forms of cancer can be cured if Udetected /Uearly

单选题The cars are tested for {{U}}defects{{/U}} before leaving the factory. A.functions B.faults C.motions D.parts

单选题What do we learn from the last paragraph?

单选题The train came to an {{U}}abrupt{{/U}} stop, making us wonder where we were.