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、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 disappears. Thus "self - healing" may be a problem for engineers. They need to use the color - changer in big construction projects that will be ______, 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.inside

B.beside

C.outside

D.above

正确答案:C

答案解析:本题有一定难度，但干扰项干扰不大，关键在理解好文章上下文意义，文章此处是说，“工程师需要把这种变色装置用在大型建筑项目上，用在外面，在阳光下”，答案是C。

2、The carCars are an important part of life in the United States. Without a car most people feel that they are poor. And even if a person is poor he doesn\'t feel really poor when he has a car. Henry Ford was the man who first started making cars in large numbers. He probably didn\'t know how much the car was going to affect American culture. The car made the United Stated a nation on wheels. And it helped make the United States what it is today. There are three main reasons why the car becomes so popular in the United States. First of all, the country is a huge one and Americans like to move around in it. The car provides the most comfortable and cheapest form of transportation. With a car people can go anylace without spending a lot of money. The second reason cars are popular is the fact that the United States never really developed an efficient and inexpensive form of public transportation. Long-distance trains have never been as common in the country as they are in other parts of the world. Nowadays there is a good system of air-service provided by planes. But it is too expensive to be used frequently. The third reason is the most important one, though. The American spirit of independence is what really made cars popular. Americans don\'t like to wait for a bus, or a train or even a plane. They don\'t like to have to follow an exact schedule. A car gives them the freedom to schedule their own time. And this is the freedom that Americans want most to have. The gas shortage has caused a big problem for Americans. But the answer will not be a bigger system of public transportation. The real solution will have to be a new kind of car, one that does not use so much gas. The real solution to the gas shortage problem is【单选题】

A.to make less cars

B.to develop a public transportation system

C.to make gas-saving cars

D.to develop train service

正确答案:C

答案解析:文章最后一句“The real solution will have to be a new kind ofcar, one that does not use so much gas”，不使用很多汽油的车，当然就是gas-saving cars（节能汽车）了。

3、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。

4、A Star Is Born1 The VLT (Very Large Telescope) is the world\'s largest telescope and is taking astronomers further back to the Big Bang than they ever thought possible. Located 2,600 meters up to the Chilean Andes, it has four huge mirrors, each about the size of a London bus. The VLT is so powerful it can spot a burning match 10, 000 kilometers away. 2 This astonishing power will allow astronomers to see events in space from the birth of stars to the collision of galaxies on the edge of the cosmos. The VLT is giving astronomers their best ever view of the cosmos. The power of the VLT to see the smallest detail at the furthest distances makes its designers amazed. 3 Take the case of Eta Carinae, one of the most explosive stars in the universe. This star produces ultraviolet laser rays (紫外线) and it will destroy itself in a few million years\' time. It is five times brighter than the sun and when it explodes it is going to be a sight worth waiting for. 4 But it is at distances of millions, even billions, of light years that the VLT really shows its power. The VLT can detect light that set out on its journey before the earth even existed. This gives astronomers their first ever detailed views of events that took place in the earliest days of the cosmos. 5 In other words, the VLT is a kind of a time machine. It takes astronomers back to a time when complete galaxies crashed into each other. The effects of these past collisions can now be seen by scientists, and astronomers believe the telescope will reveal more about these exciting events in the years to come. One day, we might be able to say we have traveled back to the beginning of time, and we will have a much clearer picture of how our planet was born. Paragraph 1____【单选题】

A.Events That Took place Before the Earth Existed

B.Power of the Telescope

C.Details of Eta Carinae

D.Invention of a Time Machine

E.Biggest Telescope

F.Ultraviolet Laser Rays

正确答案:E

答案解析:文章第1段主要介绍的是世界上最大的望远镜的大小，故E为正确答案。

5、Cell Phone Lets Your Secret OutYour cell phone holds secrets about you. Besides the names and numbers that you\'ve programmed into it, traces of your DNA linger on the device, according to a new study.DNA is genetic material that appears in every cell. Like your fingerprint, your DNA is unique to you- because you have an identical twin. Scientists today routinely analyze DNA in blood, saliva, or hair left behind at the scene of a crime. The results often help detectives identify criminals and their victims. Your cell phone can reveal more about you than you might think.Meghan J. McFadden, a scientist at McMaster University in Hamilton, Ontario, heard about a crime in which the suspect bled onto a cell phone and later dropped the ______. This made her wonder whether traces of DNA lingered on cell phones even when no blood was involved. So she and colleague Margaret Wallace of the City University of New York analyzed the flip open phones of 10 volunteers. They used swabs to collect invisible traces of the users from two parts of the phone: the outside, where the user holds it, and the speaker, which is placed at the user\'s ear.The scientists scrubbed the phones using a solution made mostly of alcohol. The aim of washing was to remove all detectable traces of DNA. The owners got their phones back for another week. Then the researchers collected the phones and repeated the swabbing of each phone once more.The scientists discovered DNA that belonged to the phone\'s speaker on each of the phones. Better samples were collected from the outside of each phone, those swabs also picked up DNA that belonged to other people who had apparently also handled the phone. Surprisingly, DNA showed up even in swabs that were taken immediately after the phones were scrubbed. That suggests that washing won\'t remove all traces of evidence from a criminal\'s device. So cell phones can now be added to the list of clues that can clinch a crime scene investigation.【单选题】

A.device

B.paper

C.file

D.document

正确答案:A

答案解析:定冠词the说明该选项所指内容在前面已经提到，即cell phone。除了device，其他选项均不能指代cell phone。