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1、Unit2Robots一、阅读理解。VitaminBcouldhelplessentheeffectsofthemostdangeroustypeofairpollution,accordingtoanewstudypublishedrecently.Inthefirststudyofitskind,ateamofinternationalresearcherslookedatthedamagecausedbyoneofthepollutantsthathavethemostsevereimpa
2、ctonhealth:PM2.5.Particulatematter,orPM,isatypeofairpollutantconsistingofsmallparticlesofdifferentsizes.PM2.5hasadiameteroffewerthan2.5micrometers,about30timessmallerthanahumanhair.Theseparticlesaresosmallthattheycangointoourrespiratorysystem(呼吸系统),r
3、esultinginlungandsystemicinflammation(炎症)andstress.TheteamfoundthatsomethingassimpleasadailyvitaminBsupplementcouldpotentiallyreducetheimpactofthetinyparticlesonthehumanbody,althoughtheystressedthattheresearchwasinitsearlystagesandthesamplesizewassma
4、ll.Forthisstudy,10volunteerswereinitiallyexposedtocleanairandgivenaplacebo(安慰剂)tochecktheirresponses.ThegroupthentookanotherplaceboforfourweeksbeforebeingexposedtoheavilypollutedairfromdowntownToronto,whereanestimated1，000carspasseveryhour.Thebadairw
5、asdeliveredtothevolunteersthroughan“oxygentype”facemask.Theexperimentwasthenrepeated,witheachvolunteertakingaBvitaminsupplementdailymadeupof2.5mgoffolicacid,50mgofvitaminB6,and1mgofvitaminB12.B6canbefoundinliver,chickenandnuts,andB12infish,meat,eggs,
6、milkandsomecereals.TheresearchersfoundthatfourweeksofBvitaminsupplementsreducedthedamageofPM2.5exposureby28%－76%.TheresultshighlighthowpreventionatanindividuallevelcouldbeusedtofighttheharmfuleffectsofPM2.5.【解题导语】 本文是一篇说明文。吸入人体内的PM2.5(细颗粒物)会导致疾病。不过，研
7、究发现维生素B在一定程度上能降低PM2.5的危害。1．WhyisPM2.5harmfultoourhealth?A．Itpollutesandpoisonstheair.B．Itistoomuchtobegotridof.C．Itcarriesvirusesanddiseases.D．Itiseasilybreathedinanddamagesourbody.D 解析：细节理解题。根据第二段中的“Theseparticlesaresosmall...inflammation(炎症)andstre
8、ss.”可知，PM2.5(细颗粒物)很小，能进入我们的呼吸系统，导致肺部和全身炎症。2．WhatcanweinferfromParagraph3?A．Theprocessoftheresearchwasnotscientific.B．Thiskindofresearchhasbeendonemanytimes.C．Furtherstudiesareneededtoconfirmtheirfindings.D．VitaminBishardtoobtaininpeople’sdailylife.C
