2017年成人高考专升本英语真题.pdf

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2017成人高考专升本英语真题

一、阅读理解

Ifyoulookatthenightsky,you’lloftenseestarsmoving

veryquickly.Infact,theymovemuchmorequicklythantheyshould

accordingtotheirsizeandthelawsofphysics.

Scientistsdonotcompletelyunderstandwhythespeedofthese

starsissohigh.Butmanybelievethereasonisthatmuchofthe

universeismadeofsomethingcalled“darkmatter”.Groupsofstars

calledgalaxies,suchastheMilkyWay,mightevenbemadeupof90

percentdarkmatter.

Howmuchsomethingweighsdependsonwhereitis.Thesame

objectweighsonlyhalfasmuchonMarsasitdoesonEarthandalmost

threetimesasmuchonJupiter.Soscientistsprefertotalkaboutthe

mass(质量)ofsomethingratherthanhowmuchitweighs,becausemass

doesnotchange.Theycanworkoutthemassofgalaxiesbymeasuringthe

distancebetweenthemandthespeedtheymoveat.

Recently,JorgePeñarrubia,asenioracademicatEdinburgh

University,UK,andhisteamdiscoveredsomethinginteresting:Themass

oftheMilkyWayisonlyhalfasmuchasthemassofanothernearby

galaxy,Andromeda.Thisseemsstrange,anddarkmattermayexplainwhy.

Findingoutmoreaboutdarkmattercouldhelpusunderstandhow

theuniversebegan,butthisisnoteasy.Lotsofscientistswith

differenttypesofexpertknowledgeareworkingontheproblem.

Wecan’tseedarkmatter,it’sverydifficulttomeasureand

wecan’tfindoutitsmass.Unlikestars,darkmatterdoesn’tproduce

orreflectlight.Butwecanmakeagoodguessthatitistherebecause

ofthewaythingsmoveandthewaylightbends.Expertsnowthinkdark

mattermaybeverydifferentfromthematterthatwefindonEarth.

Theremayalsobefivetimesasmuchdarkmatterintheuniverseas

ordinarymatter.

1.Somethingthatweighs15kgonEarthweighsabout_____on