职称英语考试《理工类》章节练习题精选及答案0517-76

职称英语考试《理工类》章节练习题精选及

答案0517-76

1、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 _____.

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

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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 cooled 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.

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【单选题】 A.star B.Earth C.space D.planet

正确答案:C

答案解析:本题难度较大，考查词义辨析，干扰项干扰较大。根据全文的逻辑，文章此处是讨论的宇宙空间范围内的温度，而不仅仅是地球上或星体的温度，最佳答案是C。

1、Better Control of TB Seen if a Faster Cure is Found

The World Health Organization estimates that about one-third of all people are infected with bacteria that cause tuberculosis.

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