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。小编为您整理阅读判断分析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), 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。

2、The Threat to KiribatiThe people of Kiribati are afraid that one day in the not-too-distant future, their country will disappear from the face of the earth-literally. Several times this year, the Pacific island nation has been flooded by a sudden high tide. These tides, which swept across the island and destroyed houses, came when there was neither wind nor rain. "This never happened before," say the older citizens of Kiribati.What is causing these mysterious high tides? The answer may well be global warming. When fuels like oil and coal are being burned, pollutants (污染物) are released. These pollutants trap heat in the earth\'s atmosphere. Warmer temperatures cause water to expand and also create more water by melting glaciers (冰川) and polar (极地的) ice caps.If the trend continues, scientists say, many countries will suffer, Bangladesh, for example, might lose one-fifth of its land. The coral (珊瑚) island nations of the Pacific, like Kiribati and the Marshall Islands, however, would face an even worse fate-they would be swallowed by the sea. The loss of these coral islands would be everyone\'s loss. Coral formations are home to more species than any other place on earth.The people of these nations feel frustrated. The sea, on which their economies have always been based, is suddenly threatening their existence. They don\'t have the money for expensive technological solutions like seawalls. And they have no control over the pollutants, which are being released mainly by activities in large industrialized countries. All they can do is to hope that industrialized countries will take steps to reduce pollution.Scientists are not sure how serious the effects of global warming will be.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:B

答案解析:题干大意：科学家不确定全球变暖将产生多么严重的后果。文章第三段提到：If the trend continues, scientists say, many countries will suffer...would face an even worse fate. 如果按照这个趋势继续发展，很多国家将会遭受或者面临更严重的危机。也就是说科学家们还是看到了全球变暖的严峻性。故答案选B。

3、Inventor of LEDWhen Nick Holonyak set out to create a new kind of visible lighting using semiconductor alloys, his colleagues thought he was unrealistic. Today, his discovery of light-emitting diodes, or LEDs, are used in everything from DVDs to alarm clocks to airports. Dozens of his students have continued his work, developing lighting used in traffic lights and other everyday technology. On April 23,2004, Holonyak received the $500,000 Lemelson-MIT Prize at a ceremony in Washington. This marks the lOth year that the Lemelson-MIT Program at the Massachusetts Institute of Technology (MIT) has given the award to prominent inventors. "Anytime you get an award big or little. It\'s always a surprise. " Holonyrak said. Holonyak, 75, was a student of john Bardeen, an inventor of the transistor, in the early 1950s. After graduate school, Holonyak worked at Ben Labs. He later went to General Electric, where he invented a switch now widely used in house dimmer switches. Later, Holonyak started looking into how semiconductors could be used to generate light. But while his colleagues were looking at how to generate invisible light, he wanted to generate visible light. The LEDS he invented in 1962 now last about 10 times longer than incandescent bulbs, and are more environmentally friendly and effective. Holonyak, now a professor of electrical and computer engineering and physics at the University of Illinois, said he suspected that LEDs would become as commonplace as they are today, but didn\'t realize how many uses they would have. "You don\'t know in the beginning. You think you\'re doing something important. You think it\'s worth doing, but you really can\'t tell what the big payoff is going to be, and when, and how. You just don\'t know, "he said. The Lemelson. MIT Program also recognized Edith Flanigen, 75, with the $100,000 Lemelson-MIT Lifetime Achievement Award for her work on a new generation of "molecular sieves", that can separate molecules by size. Holonyak\'s colleagues thought he would fail in his research on LEDs at the time when he started it.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:A

答案解析:利用题干中的核心词colleagues作为答案线索词，找到答案相关句。根据该句内容可以推断出LEDs就是前句中提到的visible lighting using semiconductor alloys。因此选A。

4、The Threat to KiribatiThe people of Kiribati are afraid that one day in the not-too-distant future, their country will disappear from the face of the earth-literally. Several times this year, the Pacific island nation has been flooded by a sudden high tide. These tides, which swept across the island and destroyed houses, came when there was neither wind nor rain. "This never happened before," say the older citizens of Kiribati.What is causing these mysterious high tides? The answer may well be global warming. When fuels like oil and coal are being burned, pollutants (污染物) are released. These pollutants trap heat in the earth\'s atmosphere. Warmer temperatures cause water to expand and also create more water by melting glaciers (冰川) and polar (极地的) ice caps.If the trend continues, scientists say, many countries will suffer, Bangladesh, for example, might lose one-fifth of its land. The coral (珊瑚) island nations of the Pacific, like Kiribati and the Marshall Islands, however, would face an even worse fate-they would be swallowed by the sea. The loss of these coral islands would be everyone\'s loss. Coral formations are home to more species than any other place on earth.The people of these nations feel frustrated. The sea, on which their economies have always been based, is suddenly threatening their existence. They don\'t have the money for expensive technological solutions like seawalls. And they have no control over the pollutants, which are being released mainly by activities in large industrialized countries. All they can do is to hope that industrialized countries will take steps to reduce pollution.The people of Kiribati worry that one day their country will be taken away by a sudden high tide.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:A

答案解析:题干大意：基里巴斯人民担心也许有一天他们的国家会被一个突然的高潮卷走。文章开头首句提到：The people of Kiribati are afraid that one day in the not-too-distant future, their country will disappear from the face of the earth-literally. Several times this year, the Pacific island nation has been flooded by a sudden high tide. 基里巴斯人民担心在不久的将来一天，他们的国家就会从地上消失。今年有几次，太平洋岛国已经遭到突然的高潮冲淹。题干所述与文章信息一致，故答案选A。

5、Will We Take Vacation in Spaces?When Mike Kelly first set out to build his own private space-ferry service, he figured his bread-and-butter business would be lofting (发射) satellites into high-Earth orbit. Now he thinks he may have figured wrong. "People were always asking me when they could go," says Kelly, who runs Kelly Space & Technology out of San Bemardino, California. "I realized that real market is in space tourism."According to preliminary market surveys, there are 10,000 would-be-space-tourists willing to spend $1 million each to visit the final frontier. Space Adventure in Arlington, Virginia, has taken more than 130 deposits for a two-hour, $98, 000 space tour tentatively and somewhat dubiously (可疑地) set to actor by 2005. Gene Meyers of the space Island Group says: "Space is the next exotic(风光奇特的) vacation spot. "This may all sound great, but there are a few hurdles (困难). Putting a simple satellite into orbit with no oxygen, life support or return trip necessary already costs an astronomical (天文数字) $ 22,OOO/kg. And that doesn\'t include the oust of insuring rich and possibly litigious passenger. John Pike of the Federation of American Scientists acerbically (尖刻地) suggests that the entire group of entrepreneurs trying to corner (垄断) the space-tourism market have between them "just enough money to blow up one rocket."The U. S. space agency has plenty of money but zero interest in mailing space less expensive for the little guys. So the little guys are racing to do what the government has failed to do: design a reusable launch system that is inexpensive, safe and reliable. Kelly Space\'s prototype looks like a plane that has sprouted rocket engines. Rotary Rocket in Redwood City, California, has a booster with rotors to make a helicopter-style return to Earth; Kistler Aero-space in Kirkland, Washington, is piecing together its versions from old Soviet engines, shuttle-style thermal protection tiles and an elaborate parachute system. The first passenger countdowns are still years away, but bureaucrats at the Federal Aviation Administration in Washington are already informally discussing flight regulations. After all, you can\'t be too prepared, for a trip to that galaxy far, far away. For those who are intent on joining the 100-mile high club, Hilton and Budget are plotting to build space hotels. Before the Russian spaceship Mir came down, some people were talking about using it as a low-rent space hotel to reduce the cost. If a space hotel is finally built in space, and if you are thinking of staying in it, you may want to check the Michelin ratings before booking yourself a suite. Little guys, who do not have plenty of money but have great interest in space tourism, are trying to make the space travel less expensive but more reliable. 【单选题】

A.Right

B.Wrong

C.Notmentioned

正确答案:A

答案解析:依据是第3段中的该句话：少数人在争相做政府未做成功的事情，即设计一套可以再度使用的廉价、安全、可靠的发射系统。