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、Black Holes
Most 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 sun is the heaviest star in the universe.
【单选题】

A.Right

B.Wrong

C.Not mentioned

正确答案:C

答案解析:题干大意：在宇宙中，太阳是最重的星体。用中心词the sun回到原文定位，文章并未提及与太阳相关的信息。故答案选C。

2、Arctic Melt
Earth's North and South Poles are famous for being cold and icy. Last year, however, the amount of ice in the Arctic Ocean fell to a record low.
Normally, ice builds in Arctic waters around the North Pole each winter and shrinks during the summer. But for many years, the amount of ice left by the end of summer has been declining.
Since 1979, each decade has seen an 11. 4 percent drop in end of summer ice cover. Between 1981 and 2000, ice in the Arctic lost 22 percent of its thickness, becoming 1.13 meters thinner.
Last summer, Arctic sea ice reached its skimpiest levels yet. By the end of summer 2007, the ice had shrunk to cover just 4.2 million square kilometers. That's 38 percent less area than the average cover at that time of year. And it's a very large 23 percent below the previous record low, which was set just 2 years ago. This continuing trend has scientists concerned.
There may be several reasons for the ice melt, says Jinlun Zhang, an oceanographer at the University of Washington at Seattle. Unusually strong winds blew through the Arctic last summer. The winds pushed much of the ice out of the central Arctic, leaving a large area of thin ice and open water.
Scientists also suspect that fewer clouds cover the Arctic now than in the past. Clearer skies allow more sunlight to reach the ocean. The extra heat warms both the water and the atmosphere. In parts of the Arctic Ocean last year, surface temperatures were 3.5℃ warmer than average and 1.5℃ warmer than the previous record high.
With both air and water getting warmer, the ice is melting from both above and below. In some parts of the Beaufort Sea, north of Alaska and western Canada, ice that measured 3. 3 meters thick at the beginning of the summer measured just 50 centimeters by season's end.
The new measurements suggest that melting is far more severe than scientists have seen by just looking at ice cover from above, says Donald K. Perovich, a geophysicist at the U. S. Army Cold Regions Research and Engineering Laboratory in Hanover, N. H.
Some scientists fear that the Arctic is stuck in a warming trend from which it may never recover.
What can be a possible title for the passage?
【单选题】

A.What are scientists looking for in the Arctic Ocean?

B.What are scientists doing in the Arctic Ocean?

C.Why are scientists worrying about the Arctic Ocean?

D.Why are scientists interested in the Arctic Ocean?

正确答案:C

答案解析:本文讲述了科学家们担心气温上升、冰川融化，最后一句话体现了主旨，所以选C。

3、Singing Alarms Could Save the Blind
If you cannot see, you may not be able to find your way out of a burning building and that could be fatal. A company in Leeds could change all that with directional sound alarms capable of guiding you to the exit.
Sound Alert, a company run by the University of Leeds, is installing the alarms in a residential home for blind people in Sommerset and a resource centre for the blind in Columbia. ______ produce a wide range of frequencies that enable the brain to determine where the sound is coming from.
Deborah Withington of Sound Alert says that the alarms use most of the frequencies that can be heard by humans. "It's a burst of white noise that people say sounds like static on the radio," she says. "Its life-saving potential is great."
She conducted an experiment in which people were filmed by thermal-imaging cameras trying to find their way out of a large smoke-filled room. It took them nearly four minutes to find the door without a sound alarm, but only 15 seconds with one.
Withington studies how the brain processes sounds at the university. She says that the source of a wide band of frequencies can be pinpointed more easily than the source of a narrow band. Alarms basedon the same concept have already been installed on emergency vehicles.
The alarms will also include rising or falling frequencies to indicate whether people should go up or down stairs. They were developed with the aid of a large grant from British Nuclear Fuels.
【单选题】

A.Alarms

B.Alarm

C.The alarm

D.The alarms

正确答案:D

答案解析:我们知道该空的名词应出现在前文，上一句就提到“Sound Alert，is installing the alarms in a residential home…”，所以这里所要填的词也应该是the alarms。

4、Singing Alarms Could Save the Blind
If you cannot see, you may not be able to find your way out of a burning building and that could be fatal. A company in Leeds could change all that with directional sound alarms capable of guiding you to the exit.
Sound Alert, a company run by the University of Leeds, is installing the alarms in a residential home for blind people in Sommerset and a resource centre for the blind in Columbia. The alarms produce a wide range of frequencies that enable the brain to determine where the sound is coming from.
Deborah Withington of Sound Alert says that the alarms use most of the frequencies that can be heard by humans. "It's a burst of white noise ______ people say sounds like static on the radio," she says. "Its life-saving potential is great."
She conducted an experiment in which people were filmed by thermal-imaging cameras trying to find their way out of a large smoke-filled room. It took them nearly four minutes to find the door without a sound alarm, but only 15 seconds with one.
Withington studies how the brain processes sounds at the university. She says that the source of a wide band of frequencies can be pinpointed more easily than the source of a narrow band. Alarms basedon the same concept have already been installed on emergency vehicles.
The alarms will also include rising or falling frequencies to indicate whether people should go up or down stairs. They were developed with the aid of a large grant from British Nuclear Fuels.
【单选题】

A.where

B.what

C.that

D.how

正确答案:C

答案解析:选项A、B、D都不能构成语意上的连贯，而只有C构成一个句型——强调句，it's… that…这句话强调的是主语。去掉it's…that，剩下的完整句子就是“A burst of white noise， people say（插入语）,sounds like static on the radio”。

5、What Is the Coolest Gas in the Universe?
What is the coldest air temperature ever recorded on the Earth? Where was this low temperature recorded? The coldest recorded temperature on Earth was - 91℃, which occurred in Antarctica (南极洲) in 1983.
We encounter an interesting situation when we discuss temperatures in space.
Temperatures in Earth orbit actually range from about +120℃ to - 120℃. The temperature depends upon whether you are in direct sunlight or shade. Obviously, -120℃ is colder than our body can safely endure. Thank NASA science for well, de signed space suits that protect astronauts from these temperature extremes.
The space temperatures just discussed affect only our areal of the solar system. Obviously, it is hotter closer to the Sun and colder as we travel away from the Sun. Astronomers estimate temperatures at Pluto are about - 210℃. How cold is the lowest estimated temperature in the entire universe? Again, it depends upon your location. We are taught it is supposedly impossible to have a temperature below absolute zero, which is - 273℃, at which atoms do not move. Two scientists, whose names are Cornell and Wieman, have successfully _____ down a gas to a temperature barely above absolute zero. They won a Nobel Prize in Physics in 2001 for their work, not a discovery, in this case.
Why is the two scientists' work so important to science?
In the 1920s, Satyendra Nath Bose was studying an interesting theory about special light particles we now call photons (光子). Bose had trouble convincing other scientists to believe his theory, so he contacted Albert Einstein. Einstein's calculations helped him theorize that atoms would behave as Bose thought—but only at very cold temperatures.
Scientists have also discovered that ultra - cold(超冷) atoms can help them make the world's atomic clocks even more accurate. These clocks are so accurate today they would only lose one second every six million years! Such accuracy will help us travel in space because distance is velocity times time 4 ( d = v×t). With the long distances involved in space travel, we need to know time as accurately as possible to get accurate distance.
【单选题】

A.burnt

B.blown

C.cut

D.cooled

正确答案:D

答案解析:本题有一定难度，考查词义辨析，但干扰项干扰不大。可以先看选项得到信息提示。根据上下文逻辑，文章此处是说“……成功将一种气体制冷，使其温度达到……”，答案是D。