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、Cell Phone Lets Your Secret Out
Your cell phone holds secrets about you. Besides the names and numbers that you've programmed into it, traces of your DNA linger on the device, according to a new study.
DNA is genetic material that appears in every cell. Like your fingerprint, your DNA is unique to you- because you have an identical twin. Scientists today routinely analyze DNA in blood, saliva, or hair left behind at the scene of a crime. The results often help detectives identify criminals and their victims. Your cell phone can reveal more about you than you might think.
Meghan J. McFadden, a scientist at McMaster University in Hamilton, Ontario, heard about a crime in which the suspect bled onto a cell phone and later dropped the device. This made her wonder whether traces of DNA lingered on cell phones even when no blood was involved. So she and colleague Margaret Wallace of the City University of New York analyzed the flip open phones of 10 volunteers. They used swabs to collect invisible traces of the users from two parts of the phone: the outside, where the user holds it, and the speaker, which is placed at the user's ear.
The scientists scrubbed the phones using a solution made mostly of alcohol. The aim of washing was to remove all detectable traces of DNA. The owners got their phones back for another week. Then the researchers collected the phones and repeated the swabbing of each phone once more.
The scientists discovered DNA that ______ to the phone's speaker on each of the phones. Better samples were collected from the outside of each phone, those swabs also picked up DNA that belonged to other people who had apparently also handled the phone. Surprisingly, DNA showed up even in swabs that were taken immediately after the phones were scrubbed. That suggests that washing won't remove all traces of evidence from a criminal's device. So cell phones can now be added to the list of clues that can clinch a crime scene investigation.
【单选题】

A.was given

B.belonged

C.was owned

D.became

正确答案:B

答案解析:该句要表达的意思应该是：科学家在每一个手机上发现了属于手机拥有者的DNA。belong to是固定搭配，意思是：属于。A不符合句义，C和D不符合语法。

2、The Book of Life
So far, scientists have named about 1.6 million living species, and that's a just a fraction of that probably exists on Earth. With so many plants, animals and other creatures coveting the planet, it can be tough to figure out what type of spider is moving up your leg or what kind of bird is flying by.
A soon - to - be - started Web site might help. An international team of researchers has announced the creation of Web - based Encyclopedia of life( EOL). The project aims to catalog every species on Earth in a single, easy - to - use reference guide.
To get the encyclopedia started, the creators will use information from scientific databases that already exist. And eventually, in special sections of the site, nonscientist with specialized knowledge will get to join in. Bird - watchers, for example, will be able to input which bird they've seen and where. The technology for this kind of tool has only become available.
As the EOL develops, you might find it useful for school projects. The site will feature special pages for kids who are studying ecosystems (生态系统) in their neighborhoods. To make sure the encyclopedia is accurate, scientists will review much of the information added to it. People who visit the site will be able to choose to leave out pages that haven't been reviewed.
Another convenient feature of the EOL is that you'll be able to pick the level of detail you want to see to match your interest, age and knowledge. If you wanted to learn about bears for a science class report, for example, you could use the "novice" setting to get basic information about the animals. On the "expert" setting, on the other hand, you could get much more detailed information about the history, literature and exploration of bears.
It now takes years for scientist to collect all the data they need to describe and analyze species. The creator of the Encyclopedia of Life hope that their new tool will speed up that process.
The word "novice" in Paragraph 5 could be best replaced by ______.【单选题】

A.scientist

B.creator

C.beginner

D.expert

正确答案:C

答案解析:本题难度较大，需要很强的把握词义能力。本题可以先看选项得到信息提示，也可以结合原文的提示：you could use the“novice”setting to get basic information about the animals. On the “expert” setting, on the other hand, you could get much more detailed information…，可以看出，novice的意思和basic相近，和expert相反，回来看选项，C项和原文句意相近，是答案。

3、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.
The word "fraction" in the second paragraph means ______.【单选题】

A.a very small amount

B.a large area

C.an important system

D.a major source of information

正确答案:A

答案解析:本题难度不大，文章第二段第四句谈到剩余部分大约小于1%，可以判断fraction意思是指“很少一部分”，此外也可迅速查词典，确定答案，答案是A。

4、The maximum speed of this car is 150 miles per hour. 【单选题】

A.highest

B.lowest

C.minimum

D.supreme

正确答案:A

答案解析:highest：最高的，可以修饰speed，替换maximum（最大的）；minimum:最小的；lowest：最低的；supreme：级别最高的。

5、The chairman proposed that we stop the meeting.【单选题】

A.stated

B.announced

C.demanded

D.suggested

正确答案:D

答案解析:主席建议我们中止会议。本题难度不大，考查的是基本意义，干扰项干扰不大。propose和suggest都有“建议”的意思，是近义词，A项指“陈述”，B项指“宣布”，C项指“要求”和答案意义差异大，最佳答案是D。