Soal Latihan dan Jawaban Reading Comprehension 78

Monday, March 26th, 2012 - reading comprehension

Stars may be spheres, but not every celestial object is spherical. Objects in the

universe show a variety of shapes: round planets (some with rings), tailed comets,

wispy cosmic gas and dust clouds, ringed nebulae, pinwheel-shaped spiral galaxies,

and so on. But none of the shapes on this list describes the largest single entities in the

(5)  universe. These are the double radio sources, galaxies with huge clouds of radio emission

that dwarf the visible galaxies, sometimes by a factor of a hundred or more. Stretching

over distances greater than a million light-years, these radio-emitting regions resemble

twin turbulent gas clouds, typically forming dumbbell-like shapes with the visible

galaxy (when it is visible) in the center.

 

(10)  These double radio sources present astronomers with a puzzle. Their radio emission

arises from the synchrotron process, in which electrons accelerated to nearly the speed

of light move through magnetic fields. However, in view of the rate at which the radio

sources emit energy, they should disappear in a few million years as their electrons slow

down and cease producing radiation. Somehow new electrons must be continually

(15)  accelerated to nearly the speed of light, otherwise, by now almost none of the double

radio sources would be observed.

 

With the advent of high-resolution radio interferometers during the late 1970’s, part

of the answer became clear: the electrons are produced in jets that are shot out in

opposite directions from the center of galaxy. Remarkably narrow and highly directional,

(20)  the jets move outward at speeds close to the speed of light. When the jets strike the

highly rarefied gas that permcales intergalactic space, the fast-moving electrons lose

their highly directional motion and form vast clouds of radio-emitting gas.

 

Cosmic jets have ranked among the hottest topics of astronomical research in recent

years as astronomers strive to understand where they come from. Why should a galaxy

(25)   eject matter at such tremendous speeds in two narrow jets? And why are such jets not

seen in the Milky Way?

 

Reading Comprehension 78

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Your answers are highlighted below.
Question 1
The word "celestial" in line 1 could best be replaced by
A
glowing
B
visible
C
scientific
D
astronomical
Question 2
The word "entities" in line 4 is closest in meaning to
A
factors
B
processes
C
puzzles
D
objects
Question 3
In the first paragraph, the author describes objects in the universe in terms of their
A
shape
B
location
C
origin
D
color
Question 4
According to the passage, scientists do not fully understand why double radio sources
A
are not as big as some planets and stars
B
are beginning to slow down
C
cannot be observed with a telescope
D
have not eventually disappeared
Question 5
The word "their" in line 22 refers to
A
clouds
B
speeds
C
electrons
D
directions
Question 6
According to the passage, what happens when electrons and gas collide in space?
A
The gas becomes less radiated
B
The gas becomes more condensed
C
The electrons disperse
D
The electrons become negatively charged
Question 7
The author suggests that astronomers consider the study of cosmic jets to be
A
an obsolete scientific field
B
an unprofitable venture
C
a subjective debate
D
an intriguing challenge
Question 8
In what lines does the passage compare the size of double radio sources with that of other galaxies?
A
Lines 12-14
B
Lines 19-20
C
Lines 4-6
D
Lines 23-24
Question 9
Where in the passage does the author mention a technology that aided in the understanding of double radio sources?
A
Line 2
B
Line 7
C
Line 17
D
Line 21
Question 10
The paragraph following the passage most likely discusses
A
possible reasons for the presence of cosmic jets
B
the discovery of the first double radio sources.
C
specific double radio sources
D
an explanation of the synchrotron process
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