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、The development of the transistor and integrated circuits revolutionized the electronics industry by allowing components to be packaged more densely. 【单选题】

A.compactly

B.inexpensively

C.quickly

D.carefully

正确答案:A

答案解析:densely:密集地、浓厚地，与compactly（紧密地；紧凑地）意思相近；inexpensively：不贵地；quickly:迅速地、快；carefully:仔细地、小心地。

2、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.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。

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 word "smog" first appeared in 1952. 【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smog这个词最早出现于1952年。最后一段提到这个词是在1905年首次出现的。题句意思与原文不符，故选B。

4、I\'d very much like to know what your aim in life is.【单选题】

A.thought

B.idea

C.goal

D.plan

正确答案:C

答案解析:我很想知道你的人生目标是什么。本题有一定难度，虽然选项都是常用词汇，但干扰项干扰较大。aim和goal都有“目标”的意思，是近义词，A项指“思想”，B项指“想法”，D项指“计划”，最佳答案是C。

5、The high - speed trains can have a major impact on our lives.【单选题】

A.effort

B.problem

C.influence

D.concern

正确答案:C

答案解析:高铁会对我们的生活产生很大影响。本题难度不大，是送分题，干扰项可以说无干扰性，确定impact的引申意义有“影响”的意思，不难找到答案influence，