2017年职称英语试题《理工A》完形填空专项练习题
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__________(1) in Antarctica in 1983.
We encounter an interesting situation when we discuss temperatures in__________ (2).
Temperatures in Earth orbit actually range from about +120——C to -120——C. The temperature depends upon __________(3) you are in direct sunlight or shade. Obviously, -1200C is colder than our body can safely endure. Thank NASA science for well-designed space __________(4) that protect astronauts from these temperature extremes.
The space temperatures just discussed affect only our area of the solar __________(5).
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——C. How cold is the lowest estimated temperature in the entire universe? Again, it depends upon your __________(6). We are taught it is supposedly__________ (7) to have a temperature below absolute zero, which is-273"C, at which atoms do not move. Two scientists, whose names are Cornell and Wieman, have successfully cooled down a gas temperature barely __________(8) 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__________(9) about particles we now call photons. Bose had trouble__________(10) other scientists to believe__________(11)he contacted Albert Einstein. Einstein's calculations helped him theorize__________(12) behave as Bose thought--but only at very cold temperatures.
Scientists have also discovered that__________ (13) 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__________ (14) six million years! Such accuracy will help us travel in space because distance is velocity times time (d--vxt). With the long distances involved in space __________(15) to know time as accurately as possible to get accurate distance.
1.A. opened
B. occurred
C. opposed
D. operated
2.A. Earth
B. space
C. planet
D. star
3.A. whether
B. where
C. what
D. when
4.A. foods
B. beds
C. tools
D. suits
5.A. wind
B. energy
C. system
D. rays
6.A. education
B. status
C. knowledge
D. location
7.A. reasonable
B. wonderful
C. impossible
D. necessary
8.A. above
B. below
C. within
D. beyond
9.A. invention
B. theory
C. paper
D. experiment
10. A. convincing
B. begging
C. ordering
D. forcing
11. A. and
B. though
C. but
D. so
12. A. will
B. would
C. must
D. can
13. A. ultra-small
B. ultra-fast
C. ultra-hot
D. ultra-cold
14. A. any
B. each
C. every
D. some
15. A. travel
B. research
C. walk