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 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 _____ 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.for

B.in

C.on

D.with

正确答案:D

答案解析:本题有一定难度，考查介词with的用法，干扰项有一定的干扰。with support，固定搭配，指“在……帮助下”，此处指“在国际社会帮助下”，原句比较好的理解语序是：Keep the virus in a well - guarded UN laboratory with international support…，答案要根据介词的基本含义和用法来判断，答案是D。

2、We\'re happy to report that business is booming this year.【单选题】

A.risky

B.successful

C.failing

D.open

正确答案:B

答案解析:我们很高兴地向大家报告今年业绩红火。本题难度不大，booming指“景气，繁荣”，和successful“成功的”是近义词，A项指“冒险的”，C项指“衰退的”，D项指“开放的”，都不合句意，最佳答案是B。

3、We came across an old man lying in the road. 【单选题】

A.saved

B.saw

C.faced

D.encountered

正确答案:D

答案解析:come across:碰到、不期而遇，encounter和它的意思相同；save:拯救；see:看见；face:面对。

4、We\'re happy to report that business is booming this year.【单选题】

A.risky

B.successful

C.failing

D.open

正确答案:B

答案解析:我们很高兴地向大家报告今年业绩红火。本题难度不大，booming指“景气，繁荣”，和successful“成功的”是近义词，A项指“冒险的”，C项指“衰退的”，D项指“开放的”，都不合句意，最佳答案是B。

5、What Is the Coolest Gas in the Universe?What is the coldest air temperature ever recorded on the Earth? Where was this low temperature recorded? The coldest recorded temperature on Earth was - 91℃, which _____ in Antarctica (南极洲) in 1983.We encounter an interesting situation when we discuss temperatures in space.Temperatures in Earth orbit actually range from about +120℃ to - 120℃. The temperature depends upon whether you are in direct sunlight or shade. Obviously, -120℃ is colder than our body can safely endure. Thank NASA science for well, de signed space suits that protect astronauts from these temperature extremes.The space temperatures just discussed affect only our areal of the solar system. Obviously, it is hotter closer to the Sun and colder as we travel away from the Sun. Astronomers estimate temperatures at Pluto are about - 210℃. How cold is the lowest estimated temperature in the entire universe? Again, it depends upon your location. We are taught it is supposedly impossible to have a temperature below absolute zero, which is - 273℃, at which atoms do not move. Two scientists, whose names are Cornell and Wieman, have successfully cooled down a gas to a temperature barely above absolute zero. They won a Nobel Prize in Physics in 2001 for their work, not a discovery, in this case.Why is the two scientists\' work so important to science?In the 1920s, Satyendra Nath Bose was studying an interesting theory about special light particles we now call photons (光子). Bose had trouble convincing other scientists to believe his theory, so he contacted Albert Einstein. Einstein\'s calculations helped him theorize that atoms would behave as Bose thought—but only at very cold temperatures.Scientists have also discovered that ultra - cold(超冷) atoms can help them make the world\'s atomic clocks even more accurate. These clocks are so accurate today they would only lose one second every six million years! Such accuracy will help us travel in space because distance is velocity times time 4 ( d = v×t). With the long distances involved in space travel, we need to know time as accurately as possible to get accurate distance.【单选题】

A.operated

B.occurred

C.opened

D.offered

正确答案:B

答案解析:本题有一定难度，考查词义辨析，但干扰项干扰不大。可以先看选项得到信息提示。文章此处是说“……发生在1983年的南极洲”，显然，答案是B。