【EarlierthismonththeObamaAdministrationcalledforincreasedprotectionoftheworld’smostsoutherncontinentAntarctica.ScientistssayclimatechangeandhumanactivityhaveincreasinglyledtothemeltingofmassivepiecesofAn】

　　EarlierthismonththeObamaAdministrationcalledforincreasedprotectionoftheworld’smostsoutherncontinentAntarctica.ScientistssayclimatechangeandhumanactivityhaveincreasinglyledtothemeltingofmassivepiecesofAntarcticice.Thedisappearanceoficewillnotonlyaffectwildlifeintheareasuchassealsandpenguins.Themeltingwillalsocauseoceansandseasaroundtheworldtorise.

　　Thisrepresentsamajorthreatespeciallytocoastalareas.ForexampletheancientcityofVeniceItalyhaslongbeenthreatenedbyrisingsealevels.Thesituationismadeworsebythefactthatitsancientbuildingsbuiltonabodyofwatercalledalagoon(淡水湖)areslowlysinking.Whenthecitywasfoundedabout1600yearsagotheleveloftheAdriaticSeawasalmosttwometerslowerthanitistoday.

　　Risingsealevelsarenottheonlythreat.ThesaltywaterisalsodestroyingVenice’sfamousbuildingsandartworks.TheItaliangovernmentistryingtofixtheproblemwiththeconstructionofaseven-billion-dollarsystemofmovingfloodbarriers.

　　ClimatechangeisalsoleadingtothemeltingoficeinotherareassuchasMountKilimanjaroinnortheasternTanzania.ItisthehighestpointinAfricameasuringalmost6000meters.Themountainsupportsfivevegetationzonesandmanykindsofanimals.

　　Theiceglaciersonthemountainaredisappearingveryquickly.Thiswillhaveabadeffectonthemountain’secosystemsandonTanzania’stravelindustry.Alsoavaluablerecordofthousandsofyearsofweatherhistorywillalsobelostiftheicemelts.Scientistsstudypiecesofglaciertounderstandweatherpatternsfromthousandsofyearsago.

　　IntheUnitedStatestheicymassesinGlacierNationalParkinMontanamaysooncompletelydisappearbecauseofclimatechange.In1850therewereanestimated150glaciersinthemorethan400000hectarepark.

　　Thereare26glaciersremainingtoday.Scientistsestimatethattheglacierswillbegoneby2030.Warmingtemperaturesarealsothreateningthemanykindsofplantsandanimalsthatliveinthismountainecosystem.

　　1.Thewriterdevelopedthepassagemainlyby______.

　　A．givingexamples

　　B．listingreasons

　　C．makingcompa