Unit2Custommakesallthingseasy.有个好习惯，事事皆不难。学习内容题材词数建议时间得分统计做题备忘PartAText1科普知识394/10Text2商业经济396/10Text3社会生活439/10Text4科普知识401/10PartB生态环境612/10PartC文化教育473/10PartADirections：Readthefollowingtexts.Answerthequestionsbloweachtextbychoosing[A],[B],[C]or[D].Text1In1967,inresponsetowidespreadpublicconcernarousedbymedicalreportsofasbestos-relateddeaths,theNationalMedicalResearchCouncilorganizedcommitteeofinquirytoinvestigatethehealththreatsassociatedwiththeuseofasbestosinthebuildingindustry.Afterexaminingevidenceprovidedbymedicalresearchersandbuildingworkersandmanagement,theCouncilpublishedareportwhichincludedadvicefordealingwithasbestos.ThereportconfirmedthefindingsofsimilarresearchintheUnitedStatesandCanada.Exposuretorelativelysmallquantitiesofasbestosfibers,theyconcluded,wasdirectlyresponsibleforthedevelopmentofcancers,asbestosisandrelateddiseases.Takingintoaccountevidenceprovidedbyeconomistsandbuildingindustrymanagement,however,thereportassumedthatdespitetheavailabilityofothermaterials,asbestoswouldcontinuetoplayamajorroleintheBritishbuildingindustryformanyyearstocomebecauseofitsavailabilityandlowcost.Asaresult,thecouncilgaveaseriesofrecommendationswhichwereintendedtoreducetheriskstothosewhomightbeexposedtoasbestosinworkingenvironments.Theyrecommendedthat,wherepossible,asbestosfreematerialsshouldbeemployed.Incaseswhereasbestoswasemployed,itwasrecommendedthatitshouldbeusedinsuchawaythatloosefiberswerelesslikelytoentertheair.Thereportrecommendedthatspecialcareshouldbetakenduringworkinenvironmentswhichcontainasbestos.Workersshouldwearprotectiveequipmentandtakespecialcaretoremovedustfromtheenvironmentandclothingwiththeuseofvacuumcleaner.Thereportidentifiedfivefactorswhichdeterminethelevelofriskinvolved.Thestateandtypeofasbestosiscriticaltodeterminingtheriskfactors.Inaddition,dustformationwasfoundtobelimitedwhereasbestoswasusedwhenwetratherthandry.Thechoiceoftoolswasalsofoundtoaffectthequantitiesofasbestosparticlesthatentertheair.Machinetoolsproducegreaterquantitiesofdustthanhandtoolsand,wherepossible,theuseofthelatterwasrecommended.Acriticalfactortakesplaceinriskreductionintheadequateventilationoftheworkingenvironment.Whenworktakesplaceinanenclosedspace,moreasbestosparticlescirculateanditwasthereforerecommendedthatnaturalormachineventilationshouldbeused.Bycloselyfollowingthesewordsofadvice,itwasclaimedthatexposurecanbereducedtoareasonablypracticalminimum.1.Exposuretoasbestosfiberscancausecancer[A]onlywhenasbestosisusedinbuildingindustry.[B]onlywhenitisusedinlargequantities.[C]evenifitisusedinsmallquantities.[D]ifitisusedwhenwetratherthandry.2.Exposuretoasbestosfibersisharmfultopeople’shealth[A]sotheuseofasbestosislimited.[B]butasbestoswillcontinuetobeusedforalongtime.[C]soothernewkindsofmaterialsareunderdevelopment.[D]buttheywillnotbesowhenventilationdevicesareused.3.Evidencefromtheeconomistsandthebuildingindustriesshowsthat[A]exposuretoasbestosfibersiscancer-causing.[B]asbestosisinextensiveuseinbuildingindustry.[C]useofasbestosisbeingreducedgradually.[D]exposuretoasbestosfiberscanbereducedsignificantly.4.Accordingtothetext,whichofthefollowingistrue?[A]Choiceoftoolscannotaffectthequantitiesofasbestosparticlesthatentertheair.[B]Stateandtypeofasbestosismeaninglesstodeterminingtheriskfactors.[C]Quantityofasbestoshasnorelati...
