2020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、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 (北冰群) fell to a record low.Normally, ice builds in Arctic waters around the North Pole each winter and shrinks(缩小) 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 thinnest levels. 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 made scientists concerned to.There may be several reasons for the ice melt, says Jinlun Zhang, an oceanographer (海洋学家)at the University of Washington in 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 3.57 Celsius warmer than the average and 1.5c warmer than the previous record.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 was measured just 50 cm by season\'s endThe new measurements suggest that melting is far more severe than the thinking of scientists. Some scientists fear that the Arctic is stuck in a warming trend.The Beaufort Sea mentioned in paragraph 7 is an example to show ______.【单选题】

A.how accurate the new measurements are

B.how thick the ice is in it

C.how serious the problem of the ice melt in the Arctic is

D.how dangerous it is to travel to it

正确答案:C

答案解析:本题难度不大，答案依据比较明显，文章第七段和第八段谈到，夏天冰层以超出科学家预料的速度迅速融化，答案是C。

2、The most pressing problem that any country faces is how to use its scarce natural resources. 【单选题】

A.puzzling

B.difficult

C.terrifying

D.urgent

正确答案:D

答案解析:puzzling:让人疑惑的、费解的、令人感到莫名其妙的；difficult:困难的、艰难的；terrifying:可怕的、极大的；urgent:急迫的、紧急的，和pressing意思相同。

3、Seeing Red Means Danger AheadThe color red often means danger and by paying attention, accidents can be prevented. In the future, the color red also may help prevent danger at construction sites. Thanks to new work by engineers, bridge supports or other kinds of materials, could one day contain a color - changing material. It will turn red before a structure collapses or falls apart.The secret behind the color - changing material is a particular type of molecule (分子). A molecule is a group of atoms (原子) held together by chemical bonds. Molecules come in all shapes and sizes and make up everything you can see, touch or feel. How a molecule behaves depends on what kinds of atoms it contains and how they\'re held together.When a polymer (聚合物) containing a color - changing molecule called a mechanophore (机械响应性聚合物) is about to break, it produces a color. When a polymer with mechanophore molecules becomes "injured" or weak, one of the mechanophore bonds breaks and the material turns red. "It\'s a really simple detection method," says Nancy Sottos, one of the scientists who worked on the project. Sottos and her team tested the color - changing polymers in their lab. The test results proved encouraging.There is a way to get rid of the red color light. When a bright light is shone on the mechanophore, the broken bond is fixed and the red color _____. Thus "self - healing" may be a problem for engineers. They need to use the color - changer in big construction projects that will be outside, under sunlight. And sunlight will make the mechanophore\'s warning system useless.Sottos and her fellow scientists still have a lot of work to do before the color - changing molecules can be used outside the lab.【单选题】

A.repairs

B.controls

C.finishes

D.disappears

正确答案:D

答案解析:本题有一·定难度，关键在理解好文章上下文意义，文章此处是说“红色消失了”，答案是D。

4、Black HolesMost scientists agree that black holes exist but are nearly impossible to locate. A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere (球体). Astronomers (天文学家) think that at the center of a black hole there is a single point in space with infinite (无限的) density (稠密).This single point is called a singularity (奇点). If the singularity theory is correct, it means that when a massive star collapses, all the material in it disappears into the singularity. The center of a black hole would not really be a hole at all, but an infinitely dense point. Anything that crosses the black hole is pulled in by its great gravity.Although black holes do exist, they are difficult to observe. These are the reasons,?No light or anything else comes out of black holes. As a result, they are invisible to a telescope.?In astronomical terms, black holes are truly. For example, a black hole formed by the collapse of a giant star would have an event horizon (视界) only 18 miles across.?The nearest black holes would be dozens of light years away from Earth. One light year is about 6 trillion (万亿) miles. Even the most powerful telescopes could not pick out an object so small at such a great distance.In 1994 the Hubble Space Telescope provided evidence that black holes exist. There are still answers to be found, however, so black holes remain one of the mysteries of the universe. (2007年)The nearest black holes are hundreds of light years away from us.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:B

答案解析:题干大意：离我们最近的黑洞也有几百光年。用中心词nearest定位，原文倒数第二段提到：The nearest black holes would be dozens of light years away from Earth. 离地球最近的黑洞有几十光年(dozens)，而不是“hundreds”。故答案选B。

5、Light Night, Dark StarsThousands of people around the globe step outside to gaze at their night sky. On a clear night, with no clouds, moonlight, or artificial lights to block the view, people can see more than 14,000 stars in the sky, says Dennis Ward, an astronomer(天文学家) with the University Corporation for Atmospheric Research( UCAR) in Boulder, Colo. But when people are surrounded by city lights, he says, they\'re lucky to see 150 stars.If you\'ve ever driven toward a big city at night and seen its glow from a great distance, you\'ve witnessed light pollution. It occurs when light from streetlights, office buildings, signs, and other sources streams into space and illuminates (照亮) the night sky. This haze (朦胧) of light makes many stars invisible to people on Earth. Even at night, big cities like New York glow from light pollution, making stargazing difficult.Dust and particles of pollution factories and industries worsen the effects of light pollution. "If one city has a lot more light pollution than another," Ward says, "that city will suffer the effects of light pollution on a much greater scale."Hazy skies also make it far more difficult for astronomers to do their jobs.Cities are getting larger. Suburbs are growing in once dark, rural areas. Light from all this new development is increasingly obscuring (使变模糊) the faint (微弱的) light give off by distant stars. And if scientists can\'t locate these objects, they can\'t learn more about them.Light pollution doesn\'t only affect star visibility. It can harm wild life too. It\'s clear that artificial light can attract animals, making them go off course. There\'s increasing evidence, for example, that migrating (迁徙) birds use sunsets and sunrises to help find their way, says Sydney Gauthreaux Jr. , a scientist at Clemson University in South Carolina, "When light occurs at night," he says, "it has a very disruptive (破坏性的) influence." Sometimes birds fly into lighted towers, high - rises, and cables from radio and television towers. Experts estimate that millions of birds die this way every year.Light pollution occurs when ______.【单选题】

A.artificial lights illuminate the night sky

B.the moon lights up the night sky

C.too many stars are visible in the night sky

D.streetlights are turned off

正确答案:A

答案解析:本题难度不大，答案依据比较明显，在文章第二段第二句，谈到当来自街灯等人工灯光射入天空时，就会发生光污染，回来看选项，A项符合原文句意，是答案。