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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 （51）
astronomers.
observations in recent years have changed the basic（52）of how the universe
evolved and have indicated how little is known about the major forces and substances that
（53） our world
astronomers now know that luminous（發(fā)光的）matter—stars，planets and hot gas——
accounts （54） only about 0，4 percent of the universe.non-luminous components，such as black holes and intergalactic（星系間的）gas， （55）up 3.6 percent the rest is either dark matter ， about 23 percent，or dark energy，about 73 percent.
dark matter.sometimes （56）“cold dark matter，”has been known for some time.only recently have researchers come to understand the key role it （57）formation of stars，planets and even people.
we （58） our very existence to dark matter，“ said physicist paul steinhardt
and a co-author of a review on dark matter which （59）not long ago in the journal
science.
“dark matter dominated the structure （60）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 （61） a froth（泡沫）of an ocean of dark matter.the dark
matter dumps（結(jié)成塊）and the ordinary matter falls into it.that （62） 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 （63）it cannot be seen or detected directly
astronomers know it is there because of its （64）on celestial（天體的）objects that can be seen and measured.
but the most dominating force of all in the universe is called dark energy， a recently （65）power that astronomers say is causing the galaxies in the universe to separate at a faster and faster speed.
51 a worry b move c puzzle d reject
52 a understanding b value c pattern d structure
53 a changed b described c designed d shaped
54 a in b for c of d to
55 a make b keep c set d get
56 a written b called c identified d seen
57 a signed b stressed c acted d played
58 a believe b owe c feel d regard
59 a appeared b carried c published d contributed
60 a element b shape c formation d power
61 a with b as c form d beside
62a turned b worked c led d attempted
63 a unknow b interesting c different d visible
64 a form b outcome c effect d source
65 a seized b proven c caught d grasped