Whileintegrasedeletesanimmunecell'sgeneticmaterialandreplacesitwithitsown,itactslike________inawordprocessor.
PartIIICloze
Directions:Therearetwentyblanksinthefollowingpassage.Foreachblanktherearefourchoices.ChoosetheonethatbestfitsintothepassageandthenmarksyouranswerontheAnswerSheet.
In1982,MarkThatcher,thesonofMrs.Thatcherwasreported61intheSaharaDesertwhilecompetingintheGrandPrixmotorracefromParistoDakar.Thissadnews,so62,shooktheusuallycalmandunperturbedseasonedpolitician63herbalance.Thoughshedidherbesttopretendasif64hadhappenedandmadeherpublicappearancesasusual,peoplecouldnot65tonoticethatshewasnolongertheold66primeministerwhoalwayshadeverything67control.68shehadbecomeaverysadmotherwhowasunabletorecoverfromhershock.
Oneday,whenshewastospeakataluncheonparty,areportercaughther69herguardby70upthesubjectofhermissingsonagain.Shewastotallymentally71forthequestionandlostherselfcontrol.Tearswererollingdownhereyesasshesobbinglytoldthereporterthatthere72stillnonewsofMarkandthatshewasveryworriedabouthim.Shesaidthatallthecountries73hadpromisedtodotheirbesttohelpherfindherson.74thatshebrokedowncompletelyandsobbedsilentlyforquiteawhile.Graduallyshe75downandstartedtospeakas76.itwasaverymovingscenewhich77anewsideofMrs.Thatcher’scharacterthepublicdonotusuallysee,78peoplebegantotalkabouttheIronWoman’smaternallove,asentimentthatis79toallhumankind.
LaterMarkreturned80andsoundtohismother’sside,good-humoredandallsmilesasusual,asifnothingunusualhadeverhappened.TheIronWoman,however,brokedownagainaswassobbingforthesecondtime.
61.A.missingB.missedC.wantingD.wanted
62.A.expectedB.expectingC.unexpectedD.unexpecting
63.A.withB.onC.outD.off
64.A.somethingB.anythingC.nothingD.everything
65.A.missB.failC.pretendD.expect
66.A.reassuredB.self-assuredC.assuringD.self-assuring
67.A.forB.beneathC.belowD.under
68.A.InsteadB.howeverC.ThereforeD.So
69.A.intoB.outofC.onD.off
70.A.puttingB.bringingC.takingD.giving
71.A.readyB.preparedC.unpreparedD.unexpected
72.A.wasB.wereC.shouldbeD.wouldbe
73.A.concerningB.concernedC.worryingD.worried
74.A.AtB.BeforeC.AfterD.With
75.A.satB.brokeC.calmedD.became
76.A.plannedB.planningC.plansD.aplan
77.A.explainedB.exposedC.excludedD.exclaimed
78.A.howeverB.insteadC.soD.but
79.A.universalB.uniqueC.singleD.strange
80.A.safeB.safelyC.sightD.hearing
Whichissafer-stayingathome,travelingtoworkonpublictransport,orworkingintheoffice?Surprisingly,eachofthesecarriesthesamerisk,whichisverylow.However,whataboutflyingcomparedtoworkinginthechemicalindustry?Unfortunately,theformeris65timesriskierthanthelatter!Infact,theaccidentrateofworkersinthechemicalindustryislessthanthatofalmostanyofhumanactivity,andalmostassafeasstayingathome.
Thetroublewiththechemicalindustryisthatwhenthingsgowrongtheyoftencausedeathtothoselivingnearby.Itisthiswhichmakeschemicalaccidentssonewsworthy.Fortunately,theyareextremelyrare.ThemostfamousoneshappenedatTexasCity(1947),Flixborough(1974),Seveso(1976),Pemex(1984)andBhopal(1984)。
Someofthesearealwaysinthemindsofthepeopleeventhoughthelossoflifewassmall.NoonediedatSeveso,andonly28workersatFlixborough.TheworstaccidentofallwasBhopal,whereupto3,000werekilled.TheTexasCityexplosionoffertilizerkilled552.ThePemexfireatastorageplantfornaturalgasinthesuburbsofMexicoCitytook542lives,justamonthbeforetheunfortunateeventatBhopal.
Someexpertshavediscussedtheseaccidentsandusedeachaccidenttoillustrateaparticulardanger.ThustheTexasCityexplosionwascausedbytonsofammoniumnitrate(硝酸铵),whichissafeunlessstoredingreatquantity.TheFlixboroughfireballwasthefaultofmanagement,whichtookriskstokeepproductiongoingduringessentialrepairs.TheSevesoaccidentshowswhathappensifthelocalauthoritieslackknowledgeofthedangerontheirdoorstep.Whenthepoisonousgasdriftedoverthetown,localleaderswereincapableoftakingeffectiveaction.ThePemexfirewasmadeworsebyanoverloadedsiteinanovercrowdedsuburb.Thefiresetoffachainreactionosexplodingstoragetanks.Yet,byamiracle,thetwolargesttanksdidnotexplode.Hadthesecaughtfire,then3,000strongrescueteamandfirefighterswouldallhavedied.
1.Chemicalaccidentsareusuallyimportantenoughtobereportedasnewsbecause____.
A.theyareveryrare
B.theyoftencauselossoflife
C.theyalwaysoccurinbigcities
D.theyarousetheinterestofallthereaders
2.Whichofthefollowingstatementsistrue?
A.Workingattheofficeissaferthanstayingathome.
B.Traverllingtoworkonpublictransportissaferthanworkingattheoffice.
C.Stayingathomeissaferthanworkinginthechemicalindustry.
D.Workinginthechemicalindustryissaferthantravelingbyair.
3.Accordingtopassage,thechemicalaccidentthatcausedbythefaultofmanagementhappenedat____.
A.TexascityB.FlixboroughC.SevesoD.MexicoCity
4.Fromthediscussionamongsomeexpertswemaycocludethat____.
A.toavoidanyaccidentsweshouldnotrepairthefacilitiesinchemicalindustry
B.thelocalauthoritiesshouldnotbeconcernedwiththeproductionofthechemicalindustry
C.alltheseaccidentscouldhavebeenavoidedorcontrolledifeffectivemeasurehadbeentaken
D.naturalgasstoredinverylargetanksisalwayssafe
5.Fromthepassageweknowthatammoniumnitrateisakindof____.
A.naturalgas,whichcaneasilycatchfire
B.fertilizer,whichcan'tbestoredinagreatquantity
C.poisonoussubstance,whichcan'tbeusedinovercrowdedareas
D.fuel,whichisstoredinlargetanks