2020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 Dating
Nowadays 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。

1、The Guitar
The Museum of Fine Arts in the eastern city of Boston recently began showing a collection of guitars. The exhibit is called Dangerous Curves: The Art of the Guitar. It shows how the instrument developed during the past four centuries.
Probably no other musical instrument is as popular around the world as the guitar. Musicians use the guitar for almost every kind of music. Country and western music would not be the same without a guitar. The traditional Spanish folk music called Flamenco could not exist without a guitar. The sound of American blues music would not be the same without the sad cry of the guitar. And rock and roll music would almost be impossible without this instrument.
Music experts do not agree about where the guitar first was played. Most agree it is ancient. Some experts say an instrument very much like a guitar was played in Egypt more than a thousand years ago.
Some other experts say that the ancestor of the modern guitar was brought to Spain from Persia sometime in the twelfth century. The guitar continued to develop in Spain. In the seventeen-hundred it became similar to the instrument we know today.
Many famous musicians played the instrument. The famous Italian violinist Niccolo Paganinni played and wrote music for the guitar in the early eighteen hundred. Franz Schubert used the guitar to write some ofhis famous works.
One guitar in the Boston Fine Arts display was played by Les Paul. It is a very old electric guitar. Mister Parl began experimenting with ways to make an electric guitar in the nineteen-thirties. The Gibson Guitar Company began producing its famous Les Parl Guitar in 1952.
The instrument has the same shape and the same six strings as the traditional guitar, but it sounds very different. The guitar has always been important to blues music. The electric guitar Mister Paul helped develop made modern blues music possible. There have been many great blues guitarists. Yet, music experts say all blues guitar players are measured against one man and his famous guitar.
That man is B-B King. Every blues fan knows that years ago B-B King named his guitar Lucille. Lucille is so important to American music that the Smithsonian Institution in Washington D-C has asked for it. They want to display the large, beautiful black guitar in one of the museums because it is a part ofAmerican culture.
Guitar is more popular than any other musical instrument in the world.
【单选题】

A.Right

B.Wrong

C.Notmentioned

正确答案:A

答案解析:本题说的是吉他比世上任何乐器都更加受欢迎。第2段第1句和第2句说的正是这个意思。

1、Black Holes
Most 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)
The attraction of two large stars leads to gravity.
【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:C

答案解析:题干大意：两个巨大行星的引力导致重力。用数字two和中心词gravity（吸引力）回到原文定位，文章并没有相关信息。故答案选C。

1、The Smog
For 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.
Water was used to try to break up the smog.
【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:A

答案解析:题句的意思是“人们用水来驱散烟雾”。第3段第2句就有这层意思，故选A。

1、Lakes, Too, Feel Global Warming
There'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 or too 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, or UNFCCC. 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 or too 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。