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 OutYour 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、A Star Is Born1 The VLT (Very Large Telescope) is the world\'s largest telescope and is taking astronomers further back to the Big Bang than they ever thought possible. Located 2,600 meters up to the Chilean Andes, it has four huge mirrors, each about the size of a London bus. The VLT is so powerful it can spot a burning match 10, 000 kilometers away. 2 This astonishing power will allow astronomers to see events in space from the birth of stars to the collision of galaxies on the edge of the cosmos. The VLT is giving astronomers their best ever view of the cosmos. The power of the VLT to see the smallest detail at the furthest distances makes its designers amazed. 3 Take the case of Eta Carinae, one of the most explosive stars in the universe. This star produces ultraviolet laser rays (紫外线) and it will destroy itself in a few million years\' time. It is five times brighter than the sun and when it explodes it is going to be a sight worth waiting for. 4 But it is at distances of millions, even billions, of light years that the VLT really shows its power. The VLT can detect light that set out on its journey before the earth even existed. This gives astronomers their first ever detailed views of events that took place in the earliest days of the cosmos. 5 In other words, the VLT is a kind of a time machine. It takes astronomers back to a time when complete galaxies crashed into each other. The effects of these past collisions can now be seen by scientists, and astronomers believe the telescope will reveal more about these exciting events in the years to come. One day, we might be able to say we have traveled back to the beginning of time, and we will have a much clearer picture of how our planet was born. Scientists believe the VLT will tell us more about____. 【单选题】

A.its detecting power

B.millions of light years away in space

C.the location of the VLT

D.as an example

E.the birth of the earth

F.the rotation of the earth

正确答案:E

答案解析:文章最后一段最后一句提到了这句话的意思。

3、Academic papers are often part of a university\'s official file and can neither be returned to students nor duplicated. 【单选题】

A.borrowed

B.copied

C.purchased

D.destroyed

正确答案:B

答案解析:duplicate和copy都表示“复印、复制”；borrow:借入、借用；purchase：购买、购置；destroy:破坏、毁坏、消灭、摧毁。

4、Black HolesMost 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 nearest black holes are hundreds of light years away from us.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:B

答案解析:题干大意：离我们最近的黑洞也有几百光年。用中心词nearest定位，原文倒数第二段提到：The nearest black holes would be dozens of light years away from Earth. 离地球最近的黑洞有几十光年(dozens)，而不是“hundreds”。故答案选B。

5、Black HolesMost 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)Black holes are part of space.【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:A

答案解析:题干大意：黑洞是太空的一部分。用space回到原文定位，文中首段第三句提到：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). 天文学家认为黑洞的中心是太空中的一个单一的无限密度的点。第二段第一句也有信息提到：This single point is called a singularity (奇点). 这个单一的点叫做奇点。故答案选A。