共用题干 Dark Forces Dominate UniverseThe earth,moon,sun and all visible stars i...

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问题 共用题干 Dark Forces Dominate Universe

The earth,moon,sun and all visible stars in the sky make up less than one percent of
the universe.Almost all the rest is dark matter and dark energy,unknown forces that
_______(1)astronomers.
Observations in recent years have changed the basic_______(2)of how the
universe evolved and have indicated how little is known about the major forces and
substances that_______(3)our world.
Astronomers now know that luminous(发光的)matter一stars , planets and hot gas一
accounts_______(4)only about 0.4 percent of the universe.Non-luminous
components , such as black holes and intergalactic(星系间的)gas,_______(5)
up 3.6 percent.The rest is either dark matter,about 23 percent,or dark energy,about
73 percent.
Dark matter,sometimes_______(6)"cold dark matter,"has been known for some time.Only recently have researchers come to understand the key role it_______ (7)in the formation of stars,planets and even people.
"We_______(8)our very existence to dark matter,"said physicist Paul
Steinhardt and a co-author of a review on dark matter which_______(9)not long ago
in the journal Science.
"Dark matter dominated the structure_______(10)in the early universe,"
Steinhardt said."For the first few billion years dark matter contained most of the mass of the
universe. You can think of ordinary matter_______(11)a froth(泡沫)of an ocean
of dark matter. The dark matter clumps(结成块)and the ordinary matter falls into it. That
_______(12) to the formation of the stars and galaxies(星系)."
Without dark matter,"there would be virtually no structures in the universe,"
The nature of dark matter is_______(13).It cannot be seen or detected
directly. Astronomers know it is there because of its_______(14) on celestial(天体
的)objects that can be seen and measured.
But the most dominating force of all in the universe is called dark energy,a recently
________(15)power that astronomers say is causing the galaxies in the universe to
separate at a faster and faster speed.
选项 _________(3) A:changed B:described C:designed D:shaped
答案 D
解析

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