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.Radar is used to determine the characteristics of radiocarbon.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:C

答案解析:本题有较大难度，答案依据不明显，需要通读全文作出判断。通读全文后可以发现文章并未提及使用雷达来进行放射性碳测定，所以本题是未提及的，答案是C。

2、Black HolesMost scientists agree that black holes exist but are nearly impossible to locate. A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere (球体). Astronomers (天文学家) think that at the center of a black hole there is a single point in space with infinite (无限的) density (稠密).This single point is called a singularity (奇点). If the singularity theory is correct, it means that when a massive star collapses, all the material in it disappears into the singularity. The center of a black hole would not really be a hole at all, but an infinitely dense point. Anything that crosses the black hole is pulled in by its great gravity.Although black holes do exist, they are difficult to observe. These are the reasons,?No light or anything else comes out of black holes. As a result, they are invisible to a telescope.?In astronomical terms, black holes are truly. For example, a black hole formed by the collapse of a giant star would have an event horizon (视界) only 18 miles across.?The nearest black holes would be dozens of light years away from Earth. One light year is about 6 trillion (万亿) miles. Even the most powerful telescopes could not pick out an object so small at such a great distance.In 1994 the Hubble Space Telescope provided evidence that black holes exist. There are still answers to be found, however, so black holes remain one of the mysteries of the universe. (2007年)Black holes exist but are difficult to observe.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:A

答案解析:题干大意：黑洞是存在的，但是很难观察到。题干中的关键词为difficult，用它回到原文定位，在首句能找到difficult的近义词impossible。文章首句提到：Most scientists agree that black holes exist but are nearly impossible to locate. 黑洞确实存在，但很难定位(locate)，与题意信息相符，故答案选A。

3、The SmogFor over a month, Indonesia was in crisis. Forest fires raged out of control as the country suffered its worst drought for 50 years. Smoke from the fires mixed with sunlight and hot dry air to form a cloud of smog. This pollution quickly spread and within days it was hanging over neighboring countries including Malaysia, Singapore and Thailand. When the smoke combined with pollution from factories and cars, it soon became poisonous. Dangerous amounts of CO became trapped under the smog and pollution levels rose. People wheezed (喘息) and coughed as they left the house and their eyes watered immediately. The smog made it impossible to see across streets and whole cities disappeared as grey soot(烟灰) covered everything. In some areas, water was hosed (用胶管浇) from high-rise city buildings to try and break up the smog. Finally, heavy rains, which came in November. Put out the fires and clear the air. But the environmental costs and health problems will remain. Many people from South-Eastern Asian cities already suffer from breathing huge amounts of car exhaust fumes and factory pollution Breathing problems could well increase and many non-sufferers may have difficulties for the first time. Wildlife has suffered too. In lowland forests, elephants, deer, and tigers have been driven out of their homes by smog. But smog is not just an Asian problem. In fact. was world was first used in London in 1905 to describe the mixture of smoke and thick fog. Fog often hung over the capital. Sometimes the smog was so thick and poisonous that people were killed by breathing problems or in accidents. About 4, 000 Londoners died within five days as a result of thick smog in 1952. The forest animals haven\'t been affected by the smog. 【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:B

答案解析:题句的意思是“森林里的动物未曾受到烟雾的影响”。文中第4段最后一句提到一些动物由于烟雾逃出了森林。题句意思与原文有出入，故选B。

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.An atom of ordinary carbon has. six protons and eight neutrons.【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，主要答案依据在文章第二段第二句：An atom of ordinary carbon，called carbon - 12，has six protons and six neutrons谈到普通碳原子有6个质子和6个中子，显然，题干和答案依据不符，答案是B。

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. Space Adventure in Arlington has taken 130 deposits totaling $98,000 for a two-hour space tour. 【单选题】

A.Right

B.Wrong

C.Notmentioned

正确答案:B

答案解析:第2段第2句的意思是：每人交100万美元的定金，而不是总共98 000美元，从这句话中可以看出历时两个小时的太空旅行计划在2005年，该旅行是试验性的，并且在一定程度上令人质疑。因此题干的说法是错误的。