2025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。小编为您整理历年真题5道练习题，附答案解析，供您备考练习。

1、Radiocarbon DatingNowadays scientists can answer many questions about the past through a technique called radiocarbon (放射性碳), ｏｒcarbon - 14 dating. One key to understanding how ａｎｄ　why something happened is to discover when it happened.Radiocarbon dating was developed in the late 1940s by physicist Willard F. Libby at the University of Chicago. An atom of ordinary carbon, called carbon -12, has six protons (质子) ａｎｄ　six neutrons (中子) in its nucleus (原子核). Carbon - 14, ｏｒC - 14, is a radioactive, unstable form of carbon that has two extra neutrons. It returns to a more stable form of carbon through a process called decay (衰减). This process involves the loss of the extra neutrons ａｎｄ　energy from the nucleus.In Libby\'s radiocarbon dating technique, the weak radioactive emissions(放射)from this decay process are counted by instruments such as a radiation detectｏｒａｎｄ　counter. The decay rate is used to determine the proportion of C -14 atoms in the sample being dated.Carbon - 14 is produced in the Earth\'s atmosphere when nitrogen(氮) - 14, ｏｒN - 14, interacts with cosmic rays (宇宙射线). Scientists believe since the Earth was formed, the amount of nitrogen in the atmosphere has remained constant. Consequently, C -14 formation is thought to occur at a constant rate. Now the ratio of C -14 to other carbon atoms in the atmosphere is known. Most scientists agree that this ratio is useful fｏｒdating items back to at least 50,000 years.All life on Earth is made of organic molecules (分子) that contain carbon atoms coming from the atmosphere. So all living things have about the same ratio of C -14 atoms to other carbon atoms in their tissues (组织). Once an organism (有机体) dies it stops taking in carbon in any form, ａｎｄ　the C -14 already present begins to decay. Over time the amount of C - 14 in the material decreases ａｎｄ　the ratio of C - 14 to other carbon atoms goes down. In terms of radiocarbon dating, the fewer C -14 atoms in a sample, the older that sample is.When an organism dies, the C -14 in it begins to decay.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:A

答案解析:本题有一定难度，但答案依据比较明显。带着题干信息词回文章定位，文章最后一段第三句：Once an organism dies it stops taking in carbon in any form，ａｎｄ　the C - 14 already present begins to decay谈到一旦有机体死亡，就停止吸收任何形式的碳，现有的碳14也会逐渐衰变，题干是其近义解释，所以正确，答案是A。

2、Seeing Red Means Danger AheadThe colｏｒred often means danger ａｎｄ　by paying attention, accidents can be prevented. In the future, the colｏｒred also may help _____ danger at construction sites. Thanks to new work by engineers, bridge supports ｏｒother kinds of materials, could one day contain a colｏｒ- changing material. It will turn red before a structure collapses ｏｒfalls apart.The secret behind the colｏｒ- changing material is a particular type of molecule (分子). A molecule is aｇｒｏｕｐof atoms (原子) held together by chemical bonds. Molecules come in all shapes ａｎｄ　sizes ａｎｄ　make up everything you can see, touch ｏｒfeel. 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" ｏｒweak, 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 colｏｒlight. When a bright light is shone on the mechanophore, the broken bond is fixed ａｎｄ　the red colｏｒdisappears. Thus "self - healing" may be a problem fｏｒengineers. 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.throw

B.prevent

C.create

D.keep

正确答案:B

答案解析:本题难度不大，考查的是动词的词义辨析，干扰项干扰不大，此处是说，“在未来，红色可以帮助建筑场所阻止危险的发生”，答案是B。

3、Lakes, Too, Feel Global WarmingThere\'s no doubt, In the last few decades, the average temperature on Earth has been higher than it has been in hundreds of years. Around the world, people are starting to measure the effects of global warming ａｎｄ　trying to figure out what to do about it.Scientist recently used satellites to study the temperatures of lakes around the world ａｎｄ　they found that lakes are heating up. Between 1985 ａｎｄ　2009, satellites recorded the night time temperatures of the surfaces of 167 lakes. During those 24 years, the lakes got warmer by an average of about 0.045 degree Celsius per year.In some places, lakes have been warming by as much as 0.10 degree Celsius per year. At that rate, a lake may warm by a full degree Celsius in just 10 years. That difference may seem small you might not even notice it in your bath. But in a lake, slightly warmer temperatures could mean more algae (水藻) ａｎｄ　algae can make the lake poisonous to fish.The study shows that in some regions, lakes are warming faster than the air around them. This is important because scientists often use measurements of air temperature to study how Earth is warming. By using lake temperatures as well, scientists can get a better picture of global warming. The scientists say data on lakes give scientists a new way to measure the impact of climate change around the world.That\'s going to be useful, since no matter the country is too big ｏｒtoo small can\'t ignore climate changes. Scientists aren\'t the only ones concerned. Everyone who lives on Earth is going to be affected by the rapid warming of the planet. Many world leaders believe we might be able to do something about it, especially by reducing the amount of greenhouse(温室) gases we put into the air.That\'s why the United Nations started the Framework Convention on Climate Change, ｏｒUNFCCC. Every year the convention meets, ａｎｄ　representatives from countries around the world gather to talk about climate change ａｎｄ　discuss global solutions to the challenges of a warming world.Global warming is less threatening to small countries.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:B

答案解析:本题难度不大，答案依据比较明显，在文章第五段第一到第三句：That\'s going to be useful, since no country is too big ｏｒtoo small to ignore climate changes. Scientists aren\'t the only ones concerned. Everyone who lives on Earth is going to be affected by the rapid warming of the planet. 谈到无论大国家还是小国家都要受到气候变暖的影响，题干却说 less threatening to small countries，和原文句意不符，答案是B。

4、A Great Quake Coming?Everyone lives in San Francisco knows that earthquakes are common in the Bay Area ａｎｄ　they can devastate. In 1906, fｏｒexample, a majｏｒquake destroyed about 28000 buildings ａｎｄ　killed hundreds, perhaps thousands of people. Residents now wonder when will the next "Big One" strike. It\'s bound to happen someday. At least seven active fault(断层) lines run through the San Francisco area. Faults are places where pieces of Earth\'s crust (地壳) slide past each other. When these pieces slip, the ground shakes.To prepare fｏｒthat day, scientists are using new techniques to reanalyze the 1906 earthquake ａｎｄ　predict how bad the damage might be when the next one happens.One new finding about the 1906 quake is that the San Andreas Fault split apart faster than scientists had assumed at the time. During small earthquakes, faults rupture(断裂) about 2.7 kilometers persecond. During bigger quakes, however, ruptures can happen faster than 3.5 kilometers persecond.At such high speeds, massive amounts of pressure build up, generating underground waves that can cause more damage than the quake itself. Lucky fｏｒSan Francisco, these pressure pulses (脉冲) traveled away from the city during the 1906 event.Looking ahead, scientists are trying to predict when the next majｏｒquake will occur. Records show that earthquakes were common before 1906. Since then, the area has been relatively quiet. Patterns in the data, however, suggest that the probability of a majｏｒearthquake striking the Bay Area before 2032 is at least 62 percent.New buildings in San Francisco are quite safe in case of future quakes. Still, more than 84 percent of the city\'s buildings are old ａｎｄ　weak. Analyses suggest that another massive earthquake would cause extensive damage.People who live there today tend to feel safe because San Francisco has remained pretty quiet fｏｒa while. According to the new research, however, it\'s not a matter that whether "the Big One" will hit here. It\'s just a matter of when.The San Francisco area is located above several active fault lines.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:A

答案解析:本题难度不大，找到答案依据不难。答案依据在第一段第五句：At least seven active fault lines run through the San Francisco area，至少有七条断层地带穿越旧金山，所以本题正确，答案是A。

5、Walking to Exercise the BrainDo you think sitting ａｎｄ　studying all the time will improve students grades? Think again. Getting some exercise may help, too.New research with older people suggests that taking regular walks helps them pay attention better than if they didn\'t exercise.Previous research had shown that mice learn, remember ａｎｄ　pay attention better after a few weeks of working out on a running wheel. Mice that exercise have greater blood flow to the brain than those who don\'t. Their brain cells also make more connections.Neuroscientists (神经科学家) from the University of Illinois at Urbana Champaign wanted to find out if the same thing is true fｏｒpeople. First, they measured the physical fitness of 41 adults, ages 58 to 77, after each person walked I mile. Then, participants looked at arrows on a computer screen ａｎｄ　had to use computer keys to show which way one particular arrow was pointing.Adults who were physically fit were faster at the arrow task, ａｎｄ　their answers were just as accurate as their less - fit peers, the researchers found. The fitter participants also had more blood flow to a part of their brain responsible fｏｒpaying attention ａｎｄ　making decisions.In a second study, 15 elderly people who completed a 6 - month aerobic - training (有氧运动) course were faster at attention tasks compared with 14 seniors who just did stretching ａｎｄ　toning (韵律操) exercises fｏｒthe same amount of time.So, even going fｏｒa walk every 2 ｏｒ3 days fｏｒjust 10 to 45 minutes can help. That should be good news fｏｒthe elderly.The effects of exercising on the brains of younger people haven\'t been studied yet. Still, it can\'t hurt to take occasional breaks ａｎｄ　go fｏｒa walk ｏｒrun around with friends. Whatever you do, though, don\'t try to read ａｎｄ　walk at the same time. You could end up hurting yourself!It can be good fｏｒhealth when one takes a walk every 2 ｏｒ3 days fｏｒat least ______.【单选题】

A.3 minutes

B.45 minutes

C.30 minutes

D.10 minutes

正确答案:D

答案解析:本题有一定难度，需要认真阅读文章。答案依据在文章第七段。带着题干信息词回到文章定位。第七段第一句谈到，每两三天出去散步10到45分钟会对健康有益，回来看选项，很明显，D是近义解释，是答案。