1安顺市第一高级中学高一英语导学案必修三【背景阅读材料】AASANDSTORMstruckBeijingyesterday,coveringhomes,streetsandcarsinbrowndustandleavingtheskiesamurkyyellowasthecitysuffereditsworstpollutioninyearsaheadofthe2008SummerOlympics.Thesandstormoriginated(起源)ontheborderofChinaandMongoliaandstartedaffectingBeijingonSundaynight.“Unliketheparticulate(微粒的)matterthatoftenexistsinBeijing’sair,thesuspendinggranuleshittingthecitytodayarebigger,thoughstilllessthan100micronsindiameter,”saidWangXiaoming,anofficialwiththemunicipalenvironmentalprotectionbureau(局).“That’swhywefeelsandisrainingdown.”12安顺市第一高级中学高一英语导学案必修三TheparticulatematterthatoftenhoversoverBeijingismostlylessthan10micronsindiameter,headded.TheBeijingEnvironmentalProtectionBureauwarnedthesandstormcouldbeharmful.“Sandstormscanaffectthehumanbody,especiallytherespiratory(呼吸的)system,”anofficialwiththebureausaid.Hospitalshavedealtwithasharpincreaseinpatientswithrespiratorydiseases,andnews-paperswarnedpeopletowearmasksoutdoors.Sandstormscouldeasilyoccuratplaceswithlittlerainfall,scarcevegetationandfrequentgales,saidQiaoLin,anexpertwiththeChinaMeteorologicalAdministration.NorthernChinaexperiencessandstormsalmosteveryspring.ThesituationisworsenedbyhighertemperaturesthisspringandtheprolongeddroughtinnorthernChina,Qiaosaid.Chinalaunchedanafforestation(造林)projectin2000intheInnerMongoliaAutonomousRegion,whichisregardedasthesourceofsandstorm.Theproject,however,hasnotbeenabletocontrolthedesertification.BNWChinasandstormshutsairports,schoolsBEIJING--AsandstormhitregionsofnorthwestChinaThursday,delayingflights,strandingthousandsofpassengersandforcingschoolstosuspend(暂停)classes.Partsoffiveprovincialregionswereaffected,includingXinjiangUygurAutonomousRegion,NingxiaHuiAutonomousRegion,InnerMongoliaAutonomousRegion,andtheprovincesofGansuandShaanxi,theNationalMeteorologicalCentersaid.ThesandstormhittheGansuprovincialcapitalofLanzhouinthemorningandreducedvisibility(能见度)ytolessthan500meters,saidXuDongbei,chiefforecasterofthecity'sobservatory.FurtherwestinDunhuang,atouristdestinationfamousforBuddhistgrottoes,thesandstormlastedabout16hoursstartingat2:30a.m.Maximumwindspeedsreached24.3meterspersecondandvisibilityfellto20m."Intermsofintensityandduration,[sucha]sandstormwasrarelyseenoverthepastdecade(十年),"saidLiGuanglin,chiefforecasterofthecity'sobservatory.Thesandstormdelayedtwoflightsandforcedmanyschoolstosuspendclasses,localofficialssaid."Agriculturemightsufferseriousdamagefromthesandstorm.Isawthestrongwindsweptawaymanygreenhouseroofs,cottonseedlingsandyounggrapesonthevine.Sometreesandelectricalpoleswerebroken,"saidGaoHua,oftheDunhuangMunicipalForestryBureau.Thelocalgovernmentiscalculatingthelosses.InYinchuan,capitalofNingxiaHuiAutonomousRegion,peopleonthestreetwereseencoveringtheirmouthsandnosestightly.Someworeaplasticboxontheirheadstokeepoutsand.AtHedongAirport,12flightsweredelayed.Localmeteorological(气象的)expertsadvisedcitizenstostayindoorsasmuchaspossible,especiallytheelderlyandchildren.Theyalsowarnedpeoplenottostandunderbillboardsortrees.Similarconditionsprevailedinotherprovinces.AtBaitaAirportinHohhot,capitalofInnerMongoliaAutonomousRegion,29flightsweredelayedandthreeotherswerecancelled(取消)duetopoorvisibilityandstrongwind,strandingthousandsofpassengers,officialssaid.23安顺市第一高级中学高一...