2019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 dentist has decided to extract her bad tooth.【单选题】

A.takeout

B.repair

C.push in

D.dig

正确答案:A

答案解析:题干大意：牙医已经决定给她把坏牙拔掉。extract a tooth：拔牙。选项中，take out：取出，去掉，符合题意。repair：修理。push in：推进，闯入。dig：挖。故答案选A。

2、The Threat to Kiribati
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. 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.
Some industrialized countries are unwilling to spend money in reducing pollution.
【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:C

答案解析:题干大意：一些工业化国家不愿意花钱减少污染。文章最后一句提到：All they can do is to hope that industrialized countries will take steps to reduce pollution. 所有他们能做的就是希望工业化国家能采取措施减少污染。但是这并没有说明工业化国家不愿意花钱减少污染。故答案选C。

3、What Do Dreams Tell Us?
Why do we dream? Do dreams have meanings? These are questions which have troubled man for thousands of years. The oldest surviving book on the interpretation of dreams is Egyptian and is nearly 4,000 years old. In ancient Greece, it was thought that people who were ill could be cured by telling their dreams. They would relate their dreams to their doctors who would tell them what they meant and then give them medicine to make them well. The ancient Chinese believed that if a pregnant woman dreamed of a bear, she would have a son, and if she dreamed of a snake, she would have a daughter. There are many stories about dreams foretelling (预言) the future.
We certainly do not now believe that dreams foretell the future. Most scientists believe that dreams are based on events in our own life and on our feelings. The events are usually very recent, mostly within the last two days. Our emotions, on the other hand our wishes, hopes and fears may go back many years, even to early childhood.
In a dream, events are altered. A dream may contain parts of many real-life events. Most importantly, something that cannot be shown directly may be shown indirectly. For example, you might dream of driving a large car. This could mean not that you want to have a larger car, but that you desire power, and maybe you want to control other people. Again, you may dream that you are an actor in a play. The play is about to start, but you have completely forgot your lines. This dream may seem strange because you are not interested in acting, and you never want to be in a play. But the dream may mean that you have some other problem that you feel is too difficult for you to solve.
Psychologists believe that dreams may be helpful to us. Indeed, people who have been allowed to sleep in experiments, but not allowed to dream, have become anxious and restless. And when they are later allowed to sleep as much as they like, they dream more than ever to make us for the lost "dream time".
If you dream of driving a large car, it could mean that you want ______.
【单选题】

A.power

B.quiet and happy

C.events

D.experiments

E.diseases

F.worried and nervous

正确答案:A

答案解析:根据题干线索词driving a car定位原文至第三段第四句：For example, you might dream of driving a large car. This could mean not that you want to have a larger car, but that you desire power...句中的this即指dream of driving a car, desire作为动词与want同义。由此推断，句中画线部分即为所需添加成分，而A选项属于原文复现，故A为正确答案。

4、Seeing Red Means Danger Ahead
The color red often means danger and by paying attention, accidents can be prevented. In the future, the color red also may help prevent danger at construction sites. Thanks to new work by engineers, bridge supports or other kinds of materials, could one day contain a color - changing material. It will turn red before a structure collapses or falls apart.
The secret behind the color - changing material is a particular type of molecule (分子). A molecule is a group of atoms (原子) held together by chemical bonds. Molecules come in all shapes and sizes and make up _____ you can see, touch or feel. How a molecule behaves depends on what kinds of atoms it contains and how they're held together.
When a polymer (聚合物) containing a color - changing molecule called a mechanophore (机械响应性聚合物) is about to break, it produces a color. When a polymer with mechanophore molecules becomes "injured" or weak, one of the mechanophore bonds breaks and the material turns red. "It's a really simple detection method," says Nancy Sottos, one of the scientists who worked on the project. Sottos and her team tested the color - changing polymers in their lab. The test results proved encouraging.
There is a way to get rid of the red color light. When a bright light is shone on the mechanophore, the broken bond is fixed and the red color disappears. Thus "self - healing" may be a problem for engineers. They need to use the color - changer in big construction projects that will be outside, under sunlight. And sunlight will make the mechanophore's warning system useless.
Sottos and her fellow scientists still have a lot of work to do before the color - changing molecules can be used outside the lab.
【单选题】

A.nothing

B.anyone

C.someone

D.everything

正确答案:D

答案解析:本题难度不大，考查不定代词everything的用法，本题可以先看选项，得到信息提示，很明显，答案是D。

5、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.
The radiocarbon dating technique is only about 40 years old.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:B

答案解析:本题有一定难度，需要认真寻找答案依据。主要答案依据在文章第二段第一句：Radiocarbon dating was developed in the late 1940s谈到放射性碳测定法源于20世纪40年代，显然，早就超过了40年历史，所以本题错误，答案是B。