2021年职称英语考试《理工类》考试共65题，分为单选题和多选题和判断题和计算题和简答题和不定项。小编每天为您准备了5道每日一练题目（附答案解析），一步一步陪你备考，每一次练习的成功，都会淋漓尽致的反映在分数上。一起加油前行。

1、One Good Reason to Let Smallpox LiveIt\'s now a fair bet that we will never see the total extinction (灭绝) of the smallpox (天花) virus. When smallpox was completely got rid of in the world, scientists wanted to _____ the killer virus in the last two labs, one in the US and one in Russia. They asked: If smallpox has truly gone from the planet, what point was there in keeping these reserves?In reality, of course, it was naive to imagine that everyone would let go of such a powerful potential weapon. Undoubtedly several nations still have a few vials (小药瓶). And the last "official" stocks of live Virus bred mistrust of the US and Russia, for no obvious gain.Now American researchers have found an animal model of the human disease, opening the way for tests on new treatments and vaccines(疫苗). So once again there\'s a good reason to the virus, just in keep the disease puts in a reappearance.How do we case with the mistrust of the US and Russia? deal. Keep the virus Simple international support in a well - guarded UN laboratory that\'s open to all countries. The US will object, of course, just as it with a multilateral (多边的) approach to just about everything. But it doesn\'t mean the idea is rejects. If the virus is useful, then let\'s wrong it the servant of all humanity make not just a part of it.【单选题】

A.destroy

B.improve

C.change

D.transport

正确答案:A

答案解析:本题有一定难度，考查词义辨析，干扰项有一定的干扰。文章此处是说“当天花病毒从世界上完全被消灭时，科学家也想消灭在最后两个实验室拥有的这种致命病毒”，此处要用“消灭”的意思，答案是A。

2、Inventor of LEDWhen Nick Holonyak set out to create a new kind of visible lighting using semiconductor alloys, his colleagues thought he was unrealistic. Today, his discovery of light-emitting diodes, or LEDs, are used in everything from DVDs to alarm clocks to airports. Dozens of his students have continued his work, developing lighting used in traffic lights and other everyday technology. On April 23,2004, Holonyak received the $500,000 Lemelson-MIT Prize at a ceremony in Washington. This marks the lOth year that the Lemelson-MIT Program at the Massachusetts Institute of Technology (MIT) has given the award to prominent inventors. "Anytime you get an award big or little. It\'s always a surprise. " Holonyrak said. Holonyak, 75, was a student of john Bardeen, an inventor of the transistor, in the early 1950s. After graduate school, Holonyak worked at Ben Labs. He later went to General Electric, where he invented a switch now widely used in house dimmer switches. Later, Holonyak started looking into how semiconductors could be used to generate light. But while his colleagues were looking at how to generate invisible light, he wanted to generate visible light. The LEDS he invented in 1962 now last about 10 times longer than incandescent bulbs, and are more environmentally friendly and effective. Holonyak, now a professor of electrical and computer engineering and physics at the University of Illinois, said he suspected that LEDs would become as commonplace as they are today, but didn\'t realize how many uses they would have. "You don\'t know in the beginning. You think you\'re doing something important. You think it\'s worth doing, but you really can\'t tell what the big payoff is going to be, and when, and how. You just don\'t know, "he said. The Lemelson. MIT Program also recognized Edith Flanigen, 75, with the $100,000 Lemelson-MIT Lifetime Achievement Award for her work on a new generation of "molecular sieves", that can separate molecules by size. Holonyak said that you should not do anything you are not interested in.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:C

答案解析:利用句中出现的核心词interested作为答案线索，发现文章中没有出现该词，也没有出现与该词词义相关的其他词，而且也没有涉及这方面的内容，因此选C。

3、Arctic MeltEarth\'s North and South Poles are famous for being cold and icy. Last year, however, the amount of ice in the Arctic Ocean fell to a record low. Normally, ice builds in Arctic waters around the North Pole each winter and shrinks during the summer. But for many years, the amount of ice left by the end of summer has been declining. Since 1979, each decade has seen an 11. 4 percent drop in end of summer ice cover. Between 1981 and 2000, ice in the Arctic lost 22 percent of its thickness, becoming 1.13 meters thinner. Last summer, Arctic sea ice reached its skimpiest levels yet. By the end of summer 2007, the ice had shrunk to cover just 4.2 million square kilometers. That\'s 38 percent less area than the average cover at that time of year. And it\'s a very large 23 percent below the previous record low, which was set just 2 years ago. This continuing trend has scientists concerned. There may be several reasons for the ice melt, says Jinlun Zhang, an oceanographer at the University of Washington at Seattle. Unusually strong winds blew through the Arctic last summer. The winds pushed much of the ice out of the central Arctic, leaving a large area of thin ice and open water. Scientists also suspect that fewer clouds cover the Arctic now than in the past. Clearer skies allow more sunlight to reach the ocean. The extra heat warms both the water and the atmosphere. In parts of the Arctic Ocean last year, surface temperatures were 3.5℃ warmer than average and 1.5℃ warmer than the previous record high. With both air and water getting warmer, the ice is melting from both above and below. In some parts of the Beaufort Sea, north of Alaska and western Canada, ice that measured 3. 3 meters thick at the beginning of the summer measured just 50 centimeters by season\'s end. The new measurements suggest that melting is far more severe than scientists have seen by just looking at ice cover from above, says Donald K. Perovich, a geophysicist at the U. S. Army Cold Regions Research and Engineering Laboratory in Hanover, N. H. Some scientists fear that the Arctic is stuck in a warming trend from which it may never recover. Why is the ice melting from both above and below?【单选题】

A.Because extra heat warms the air.

B.Because extra heat warms the water.

C.Because the temperature above the water is higher.

D.Both A and B.

正确答案:D

答案解析:根据第7段第1句With both air and water getting warmer可知。

4、Chinese people tend to use plants to remedy disease. 【单选题】

A.diagnose

B.cure

C.evaporate

D.revise

正确答案:B

答案解析:remedy和cure都表示“治疗”；diagnose:诊断、找出毛病；evaporate：使……蒸发、（像蒸汽般）消失；revise:修订、校对、修改。

5、Snow RangerThe two things, snow and mountains, which are needed for a ski area are the two things that cause avalanches, large mass of snow and ice crushing down the side of a mountain, often called "White Death. "It was the threat of the avalanche and its record as a killer of man in the western mountains that created the snow ranger. He first started on avalanche control work in the winter of 1937, 38 at Alta, Utah, in Wasatch National Forest. This mountain valley was becoming well known to skiers. It was dangerous. In fact, more than 120 persons had lost their lives in 1936 and another 200 died in 1937 as a result of avalanches before it became a major ski area. Thus, development of Alta and other major ski resorts in the west was dependent upon controlling the avalanche. The Forest Service set out to do it, and did with its corps of snow rangers. It takes many things to make a snow ranger. The snow ranger must be in excellent physical condition. He must be a good skier and a skilled mountain climber. He should have at least a high school education, and the more college courses in geology, physics, and related fields he has, the better. He studies snow, terrain, wind, and weather. He learns the conditions that produce avalanches. He learns to forecast avalanches and to bring them roaring on down the mountainsides to reduce their killing strength. The snow ranger learns to do this by using artillery, by blasting with TNT, and by the difficult and skillful art of skiing avalanches down. The snow ranger, dressed in a green parka which has a bright yellow shoulder patch, means safety for people on ski slopes. He pulls the trigger on a 75 mm. Recoilless rifle, skis waist deep in powder testing snow stability, or talks with the ski area\'s operator as he goes about his work to protect the public from the hazards of deep snow on steep mountain slopes. The passage implies that a snow ranger____. 【单选题】

A.knows how to use a pistol.

B.must write lengthy reports on his work.

C.may travel many miles when he is on duty.

D.has a long working day.

正确答案:C

答案解析:A:知道怎样使用手枪；B：必须写有关其工作的长篇报告；C：值班时可能会滑行数英里；D：工作时间很长。依据常识和已有的对文章的了解推断C最合理。如果依据原文，文章中提到了“枪”的使用，所以A不是答案。在第5段中说“雪地管理员”必须身体素质好，所以暗示答案是C。