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、Water
The second most important constituent (构成成份) of the biosphere (生物圈) is liquid water. This can only exist in a very narrow range of temperatures, since water freezes at 0℃ and boils at 100℃. Life as we know it would only be possible on the surface of a planet which had temperatures somewhere within this narrow range.
The earth's supply of water probably remains fairly constant in quantity. The total quantity of water is not known very accurately, but it is about enough to cover the surface of the globe to a depth of about two and three - quarter kilometers. Most of it is in the form of the salt water of the oceans about 97 percent. The rest is fresh, but three -quarters of this is in the form of ice at the Poles and on mountains, and cannot be used by living systems until melted. Of the remaining fraction, which is somewhat less than one percent of the whole, there is 10 -20 times as much stored underground water as there is actually on the surface. There is also a tiny, but extremely important fraction of the water supply which is present as water vapour in the atmosphere.
Water vapour in the atmosphere is the channel through which the whole water circulation (循环) of the biosphere has to pass. Water evaporated (蒸发) from the surface of the oceans, from lakes and rivers and from moist (潮湿的) earth is added to it. From it the water comes out again as rain or snow, falling on either the sea or the land. There is, as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land, but there is more rainfall over the land than over the oceans and the balance is restored by the runoff from the land in the form of rivers.
Most of the flesh water on Earth ______.【单选题】

A.is stored underground

B.is in the form of ice at the Poles and on mountains

C.is found in rivers and lakes

D.comes from the rain

正确答案:B

答案解析:本题有一定难度，需要认真读懂文章句意，答案依据比较明显，在文章第二段第四句，谈到剩下1/3的淡水以冰的形式存在在南北两极和高山上，回来看选项，B项是其近义解释，所以正确，答案是B。

2、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 half - life of C - 14 is about 25 ,000 years.
【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碳的半衰期是25，000年，所以本题是未提及的，答案是C。

3、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。

4、We explored the possibility of expansion at the conference.【单选题】

A.offered

B.investigated

C.included

D.accepted

正确答案:B

答案解析:会上我们探讨了扩张的可能性。本题难度不大，干扰项干扰不大，要确定好单词的引申意义。explore的引申意义有“探讨”考生要注意，investigate的本义是“调查”，引申意义是“研究”，是explore的近义解释，是答案。

5、Meet Your Memory
1. Memory is something that cannot be seen, touched or weighed. It is thought to be abstract. It is a set of skills rather than an object. Neither is there a single standard for judging a good or poor memory. There are a number of different ways in which a person may have a good memory.
2. Memory is generally viewed as consisting of three stages: (1) acquisition refers to learning the material; (2) storage refers to keeping the material in the brain until it is needed; (3) retrieval (提取) refers to getting the material back out when it is needed:
3. Memory consists of at least two different processes: short - term memory and long - term memory. Short - term memory has a limited capacity and a rapid forgetting rate. Its capacity can be increased by chunking (组成大块), or grouping separate bits of information into larger chunks. Long - term memory has an almost unlimited capacity.
4. One measure of memory is recall, which requires you to produce information by searching the memory for it. In aided recall, you are given cues (提示) to help you produce the information. In free - recall learning you recall the material in any order. In serial learning you recall it in the order it was presented and in paired - associate learning you learn pairs of words so that when the first word is given you can recall the second word. A second measure of memory is recognition, in which you do not have to produce the information from memory, but must be able to identify it when it is presented to you. In a third measure of memory, relearning, the difference between how long it took to learn the material the first time and how long it takes to learn it again indicates how much you remember. Relearning is generally a more sensitive measure of memory than is recognition because relearning shows retention (保持) while recognition does not. Recognition is generally a more sensitive measure than recall.
Paragraph 2 ______
【单选题】

A.Why do we forget things?

B.How do we measure memory?

C.What are the stages memory consists of?

D.What is the difference between short - term memory and long - term memory?

E.What is memory?

F.Who may have a poor memory?

正确答案:C

答案解析:本题难度不大，主旨句比较明显，是文章第二段第一句前半部分：Memory is generally viewed as consisting of three stages…回来看选项，C项What are the stages memory consists of?是对本段主旨句的近义替换，是答案。