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、Better Control of TB Seen if a Faster Cure is FoundThe World Health Organization estimates that about one-third of all people are infected with bacteria that cause tuberculosis. Most times, the infection remains inactive. But each year about eight million people develop active cases of TB, usually in their lungs. Two million people die of it. The disease has increased with the spread of AIDS and drug-resistant forms of tuberculosis. Current treatments take at least six months. Patients have to take a combination of several antibiotic drugs daily. But many people stop as soon as they feel better. Doing that can lead to an infection that resists treatment. Public health experts agree that a faster-acting cure for tuberculosis would be more effective. Now a study estimates just how effective it might be. A professor of international health at Harvard University led the study. Joshua Salomon says a shorter treatment program would likely mean not just more patients ______. It would also mean fewer infectious patients who can pass on their infection to others. The researchers developed a mathematical model to examine the effects of a two-month treatment plan. They tested the model with current TB conditions in Southeast Asia. The scientists found that a two-month treatment could prevent about twenty percent of new cases. And it might prevent about twenty-five percent of TB deaths. The model shows that these reductions would take place between two thousand twelve and two thousand thirty. That is, if a faster cure is developed and in wide use by two thousand twelve. The World Health Organization developed the DOTS program in nineteen ninety. DOTS is Directly Observed Treatment, Short-course. Health workers watch tuberculosis patients take their daily pills to make sure they continue treatment. Earlier this year, an international partnership of organizations announced a plan to expand the DOTS program. The ten-year plan also aims to finance research into new TB drugs. The four most common drugs used now are more than forty years old. The Global Alliance for TB Drug Development says its long-term goal is a treatment that could work in as few as ten doses.【单选题】

A.cured

B.to cure

C.being cured

D.having been cured

正确答案:A

答案解析:本句考查的是语法。根据所给的动词，我们可以猜到本句想说的是“Joshua Salomon说，疗程较短的治疗计划可能意味着不仅仅是更多病人被治好”。这里从语法分析，应该是缺一个定语，修饰patients，cure是一个及物动词，病人应是被治疗者：选项B(to cure)不能表示被动；C和D虽然有表示被动的意思，但是C是“正在被治疗”，D是“已经被治疗”，两者隐含的时态在这里均不合适，只有A是恰当的。

2、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 device. 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 ______ 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.invisible

B.nonexistent

C.visible

D.apparent

正确答案:A

答案解析:句子当中的traces指的是DNA traces(微量DNA)，而DNA traces是肉眼看不到的，所以选择invisible。

3、Waving With LightIn the Sierra Madre mountain range of west central Mexico, the native Huichol people live much the way their ancestors did without electricity. That\'s because it\'s too expensive to string power lines to the remote mountain areas where they live. To help support themselves, the Huichol create beautiful artwork. They sell their art in cities hundreds of miles away from their villages. And without electricity at home or on the road, they can only work during daylight hours. When it gets dark, they must stop whatever they\'re doing. Now, a team of scientists, designers, and architects are using new technologies to provide the Huichol with light after the sun sets. The scientists\' technique involves weaving tiny electronic crystals into fabrics that can be made into clothes, bags, or other items. By collecting the sun\'s energy during the day, these lightweight fabrics provide bright white light at night. Their inventors have named the fabrics "Portable Lights." Portable Lights have the potential to transform the lives of people without electricity around the world, says project leader Sheila Kennedy. "Our invention," Kennedy says, "came from seeing how we could transform technology we saw every day in the United States and move it into new markets for people who didn\'t have a lot of money."At the core of Portable Light technology are devices called high-brightness light-emitting diodes, or HB LEDs. These tiny lights appear in digital clocks, televisions, and streetlights. LEDs are completely different from the light bulbs. Most of those glass bulbs belong to a type called incandescent lights. Inside, electricity heats a metal coil to about 2,200 degrees Celsius. At that temperature, bulbs give of flight we can see. Ninety percent of energy produced by incandescent lights, however, is heat and invisible. With all that wasted energy, bulbs burn out quickly. They are also easily broken. LEDs, on the other hand, are like tiny pieces of rock made up of molecules that are arranged in a crystal structure. When an electric current passes through an LED, the crystal structure produces light. Unlike incandescent bulbs, they can produce light of various colors. Within an LED, the type of molecules and their particular arrangement determines what color is produced. Why can Portable Lights emit light?【单选题】

A.Electronic crystals are woven into fabrics.

B.Items such as clothes and bags are used to carry lights.

C.The sun\'s energy is collected during the day.

D.All of the above.

正确答案:D

答案解析:文章的第2段和第3段包括了选项A、B和C所述内容。所以答案是D。

4、Radiocarbon DatingNowadays scientists can answer many questions about the past through a technique called radiocarbon (放射性碳), or carbon - 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, or C - 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 detector and 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, or N - 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 for dating 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.Radiocarbon is reliable in dating an object back to at least 50,000 years.【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，答案依据比较明显，主要答案依据在文章第四段最后一句：Most scientists agree that this ratio is useful for dating items back to at least 50,000 years谈到科学家相信，这样的比率对于测定5万多年前的物体有用，题干是其近义解释，所以正确，答案是A。

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 occurred 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 ______ 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.forcing

B.begging

C.ordering

D.convincing

正确答案:D

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。根据上下文逻辑，文章此处是说“Bose很难使其他科学家相信他的理论”，答案是D。