四级模拟考试题目.docx

四级模拟考试题目.docx

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四级模拟考试题目

大学英语四级考试模仿试题

PartIWriting（30minutes）

Directions：

Forthispartyouareallowed30minutestowriteanessaybasedontheoutlinebelow.Youshouldwriteatleast120words，andbaseyourcompositionontheoutlinegivenbelowinChinese.

当前社会上越来越多人开始在网上购买商品了，对此你有什么看法呢?

1.诸多人开始在网上购买商品

2.网上购物也许存在问题

3.我看法

TheQualityofProducts

PartIIReadingComprehension（SkimmingandScanning）（15minutes）

Directions：

Inthispart，youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.

Forquestions1-7，mark

Y（forYES）ifthestatementagreeswiththeinformationgiveninthepassage;

N（forNO）ifthestatementcontradictswiththeinformationgiveninthepassage;

NG（forNOTGIVEN）iftheinformationisnotgiveninthepassage;

Forquestions8-10，completethesentenceswiththeinformationgiveninthepassage.

Oneinthreeofuswillgetcanceratsomepointinourlives.Oncesofeareditsnamewaswhispered，thediseaseisnolongeraninevitabledeathsentence.Today，almosttwo-thirdsofthosewhodevelopcancerwillstillbealivefiveyearslater，comparedwithjusthalfin1970s.

CancerhasturnedouttobetoughertocrackthaneveryonehopedwhenU.S.PresidentRichardNixonlaunchedtheWaronCancerin1971.Butdeathratesarefalling，thankstoearlierdetectionoftumors（肿瘤）andimproveduseofexistingtreatments—mainlychemotherapyandradiotherapy.Thesuccesshasbeenbiggestforchildren：

sincethemid-1970s，deathratesfromcancersofchildhoodhavehalved.

Innerworkings.

Akeyreasonwhycancerpatientsarelivinglongeristhatscientistsnowunderstandmoreclearlywhathappenswhencellsturncancerous.Cancerbeginswhengeneswhichnormallycontrolcelldivision，growthandrepairaredamagedthroughmutation（突变）.Thesegenescanthencausecellstogrowanddivideuncontrollably，destroyingneighboringhealthycells.

MutationscanarisebychanceerrorsinDNAreplication，andgenescanalsobedamagedbycarcinogens（致癌物质）—suchastobaccochemicals，benzene，andsomefoodadditives—orultravioletlightfromsunshine.Certainvirusescanalsotriggergenemutations，suchasthehumanpapilloma（乳突淋瘤）virusthatcancausecervical（子宫颈）cancer.

Somemutatedgenesareinherited：

twoexamplesareBRCA1andBRCA2，whichtogetheraccountforabout5%ofallbreastcancercases.OthergenessuchasDBC2，EMSYandFAhavebeenimplicatedinovarian，breastandlungcancer.

Onceacellhasturnedcancerous，itdividesuntilamassofcellsformsatumor.Diagnostictestscanquicklydistinguishbetweenmalignant，orcancerous，tumorsandthosethatarebenign，orharmless.Asamalignanttumorprogresses，cellsorclumpsofcellsbreakoffandspread，aroundthebodyviathelymphaticsystemandbloodvessels.

Thelatestgenerationoftreatmentsexploitourknowledgeofwhathappenswithincancerouscells.Thesetargetproteinsandmessengerchemicals—suchasgrowthfactorsorenzymes–thattheerrantcellsneedtosurviveandgrow.

Prevalencepatterns

Indevelopedcountries，thecancermostlikelytoafflictyouisnon-melanomaskincancer，oftencausedbytheSun’sharmfulultravioletrays.Thisisusuallytreatedandcured.Melanoma，adeadlierskincancer，islesscommonbutisincreasingbyaround3%ayearintheU.S.ThoughUVlightisthecauseofmanyskincancers，thereissomeevidencethatsmallamountsmayalsohelppreventothercancers.Inthedevelopingworldthemostcommoncancersarelinkedtoinfectiousagents，suchascervicalcancerorlivercancer，causedbyhepatitis（肝炎）B.

Thebiggestkillerinindustrializednationsremainslungcancer.Formen，lungcancermortalityhasbeenfallingsince1990，mirroringapeakinpopularityofsmokingduringthe1960s.Forwomen，whocommonlytookupsmokinglater，lungcancermortalityisstillrising.TobaccoisalsorapidlybecomingtheleadingcauseofcancerinAsia.

Breastcanceraccountsforalmostoneinthreeofallcancersdiagnosedinwomeneachyear.Formen，prostatecancerisjustascommon，withthehighestratesinAfricanAmericanmenandCaribbeanmenofAfricanorigin.

Screeningforbothofthesediseaseshasimprovedsharply.Earlybreasttumorsshowuponamammogram（乳房X线照片）longbeforetheycanbefeltasalump.Morewomennowsurvivethedisease——three-quartersofwomenwhosebreastcancerwasdiagnosed10yearsagoarestillalivetoday.Similarly，aprostate-specificantigen（PSA）testhasrevolutionizedearlydiagnosisforthiscancerintheU.S.Someexpertsarguethatscreeningcanbeharmful，however.

Factoringinrisk

Dozensoffactorsaffectanindividual'sriskofgettingcancer.Smokingisthebiggestsingleriskfactor——withtobaccolinkedtoaboutathirdofallcancers.

Anotherclearlyestablishedriskfactorisexposuretoionizing（电离）radiation.ThismayberesponsibleforcancersinpeoplelivingaroundChernobylinUkraine，ToikamurainJapanandforpeopleworkinginnuclearpowerplants.Radiationmayalsohaveledtoahighincidenceofcancerinthosewhowitnessedearlynucleartestsorhavebeenincontactwithdepleteduraniummunitions，thougharecentstudyconteststhisrisk.

Riskfactorsfordevelopingbreastcancerinclude:

beingchildlessordelayingchildbearinguntilagedover30,startingperiodsearly,usinghormonereplacementtherapy，beingexposedtooestrogen-like（雌性素类）chemicals,anddrinkingoneormoreunitsofalcoholdaily.Morethanoneriskfactorisusuallyneededbeforecancercellsdevelop.

Risksposedbylivingnearoverheadpowerlinesorpetrolstops,orusingcell-phones,arelessclear.

Preventativesteps

Ifeveryonestoppedsmoking，cancerdeathscouldbecutbyone-third，researchersestimate.Movestoprotectpeoplefrompassivesmoking，inbarsforexample，aregaininggroundinmanyindustrializedcountries.

Stayingoutofsunlightandusingstrongsunscreenscouldpreventhundredsofthousandsofusfromdevelopingskincancerworldwideannually.Foodsrichinantioxidantsandbeneficialfattyacidssuchasomega-3andoleicacidfoundinoliveoil—akeyingredientofthehealthyMediterraneandiet—seemtoprotectagainstsomecancers，althoughthefindingsaremixed.

Doctorscanincreasinglyintervenedirectlytopreventcancers.Forexample，vaccinesagainsthepatitisBcouldsooncutdeathsfromlivercancer.Therearealsopreventivetherapiesthatinterferewiththeproductionofthehormoneoestrogen，implicatedinmanybreastcancers.Doctorsbelievethatitcouldhavetheratesofbreastcancerinwomenwithafamilyhistoryofthedisease.

Allthismeansthat，whilehopesoftotalcureforcancerarestillunrealistic，thediseaseisincreasinglyundercontrol.

注意：

此某些试题在答题卡1上作答；8－10题在答题卡1上。

1、ThebiggestkillerinChinaislivercancer.

2、Someviruseswillgiverisetogenemutations，whichwillresultincancers.

3、Inthe1970s,onlyone-thirdofthosewhodevelopedcancercouldbealivefiveyearslater.

4、Sunbathinghelpsuspreventourselvesfromdevelopingskincancer.

5、Non-melanomaskincancerisadeadlyskincancer.

6、Cancerpatientsarelivinglongerthanbeforebecausescientistsknowmoreaboutcancerouscells.

7、Mutatedgeneswhichareinheritedaccountforabout5%ofallcancercases.

8、Generally，one-thirdofpeoplewillgetcanceratsomepoint＿＿＿＿.

9、About＿＿＿＿ofallcancershavesomethingtodowithtobacco.

10、Itistruethat＿＿＿＿forcancerisstillimpossiblebutthediseaseisincreasinglyundercontrol.

PartIIIListeningComprehension（35minutes）

SectionA

Directions：

Inthissection，youwillhear8shortconversationsand2longconversations.Attheendofeachconversation，oneormorequestionswillbeaskedaboutwhatwassaid.Boththeconversationandthequestionswillbespokenonlyonce.Aftereachquestiontherewillbeapause.Duringthepause，youmustreadthefourchoicesmarkedA），B），C）andD），anddecidewhichthebestansweris.ThenmarkthecorrespondingletteronAnswerSheet2withasinglelinethroughthecentre.

注意：

此某些试题在答题卡2上作答。

11、A）ThewomanshouldhavetakenBusNumber15.B）ThewomangotonthebustoGrandTheatre.

C）Thewomanshouldhaveaskedtheconductor.D）Thewomanwasgoingintheoppositedirection.

12、A）ThenexttrainforBostonwillrunabitlatebecauseoftheweather.

B）ThenexttrainforBostonwillrunontimedespitetheweather.

C）ThenexttrainfromBostonwillbelateasitisrainingheavily.

D）ThetrainforBostonwillbelateasitisfoggy.

13、A）Stayathomeandreviewthelesson.B）Stayathomeandhaveagoodrest.

C）Gosomewhereelse.D）Gototheconcert.

14、A）TheTVprogramafterthenewsreport.B）WhetherthereisadocumentaryabouttheMiddleEast.

C）Thenewsheadlinesontoday’snewspaper.D）Theman’sfeelingaboutthedocumentary.

15、A）Atasupermarket.B）Atabakery.

C）Atanice-creamhouse.D）Atarestaurant.

16、A）Alanisverycareless.B）Alanisweakinhealth.

C）Alanhasgoodfriends.D）Alanisdisappointed.

17、A）it'snotworthseeingatall.

B）ItsbetterthanTVprogramsanyway.

C）it'sagoodchangeforsomeonewhostaysathomeforalongtime.

D）it'sabitterrible.

18、A）Shehasapaininherneck.B）Sheisverybusywithwork.

C）Shefeelsweak.D）Sheworksinthelaundry.

Questions19to22arebasedontheconversationyouhavejustheard.

19、A）Attheairport.B）Atthetravelagency.

C）Attherailwaystation.D）Attheinformationcenter.

20、A）Every24hours.B）Every22andahalfhours.

C）Everymorning.D）Everynoon.

21、A）At11:

40Monday.B）At11:

40Wednesday.

C）At22:

30Tuesday.D）At22:

30Wednesday.

22、A）Thepassengerhasbookedatrainticket.

B）Thepassengerhasbookedaplaneticket.

C）Thepassengerhasn’tdecidedwhetherhewillgobytrainorbyplane.

D）Thepassengerwillcomebacktobookatraintick