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 destroy 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 _____ 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.more

B.few

C.a few

D.a lot

正确答案:C

答案解析:本题有一定难度，本题可用排除法，文章里没有出现比较的含义，所以more可以排除掉，a lot后面不能接名词，不能说a lot vials，所以也可以排除掉，依据上下文逻辑，文章此处是说“毫无疑问，几个国家仍有几瓶（病毒）”，此处要用“几个”的意思，只能用a few，答案是C。

2、Rodman met with Tony to try and settle the dispute over his contract.【单选题】

A.solve

B.avoid

C.mark

D.involve

正确答案:A

答案解析:罗得曼和托尼会面，试图解决有关他合同的争论。本题难度不大，是送分题，干扰项干扰不强。settle的意思是“解决”，和solve“解决”是同义词，involve指“包含，牵涉”，答案是A。

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 _____ 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 disappears. 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.nothing

B.anyone

C.someone

D.everything

正确答案:D

答案解析:本题难度不大，考查不定代词everything的用法，本题可以先看选项，得到信息提示，很明显，答案是D。

4、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。

5、They agreed to modify their policy.【单选题】

A.clarify

B.change

C.define

D.develop

正确答案:B

答案解析:题干大意：他们同意修改他们的政策。画线词modify：改动，修改。选项中，clarify：澄清，阐明。change：改变，与画线词意思一致，符合题意。define：界定。develop：发展。故答案选B。