专题5 阅读理解_40

（2016·北京）阅读理解。
 
CaliforniaCondor’sShockingRecovery
 
CaliforniacondorsareNorthAmerica’slargestbirds,withwing-lengthofupto3meters.Inthe1980s,electricallinesandleadpoisoning(铅中毒)nearlydrovethemtodyingout.Now,electricshocktrainingandmedicaltreatmentarehelpingtorescuethesebigbirds.
 
Inthelate1980s,thelastfewcondorsweretakenfromthewild,andtherearenowmorethan150flyingoverCaliforniaandnearbyArizona,UtahandBajainMexico.
 
Electricallineshavebeenkillingthemoff.“Astheygointorestforthenight,theyjustdon’tseethepowerlines,”saysBruceRideoutofSanDiegoZoo.Theirwingscanbridgethegapbetweenlines,resultinginelectrocution(电死)iftheytouchtwolinesatonce.
 
Soscientistshavecomeupwithashockingidea.Tallpoles,placedinlargetrainingareas,teachthebirdstostayclearofelectricallinesbygivingthemapainfulbutundeadlyelectricshock.Beforethetrainingwasintroduced,66%ofset-freedcondorsdiedofelectrocution.Thishasnowdroppedto18%.
 
Leadpoisonoushasprovedmoredifficulttodealwith.Whencondorseatdeadbodiesofotheranimalscontaininglead,theyabsorblargequantitiesoflead.Thisaffectstheirnervoussystemsandabilitytoproducebabybirds,andcanleadtokidney(肾)failuresanddeath.SocondorswithhighlevelsofleadaresenttoLosAngelesZoo,wheretheyaretreatedwithcalciumEDTA,achemicalthatremovesleadfromthebloodoverseveraldays.Thisworkisstartingtopayoff.Theannualdeathrateforadultcondorshasdroppedfrom38%in2000to5.4%in2011.
 
Rideout’steamthinksthattheCaliforniacondors’averagesurvivaltimeinthewildisnowjustundereightyears.“Althoughthesemeasuresarenoteffectiveforever,theyarevitalfornow,”hesays.“Theyaretrulygoodbirdsthatarewortheveryeffortweputintorecoveringthem.”
 
【小题1】Californiacondorsattractresearchers’interestbecausethey.A．areactiveatnightB．hadtobebredinthewildC．arefoundoninCaliforniaD．almostdiedoutinthe1980s【小题2】Researchershavefoundelectricallinesare.A．blockingcondors’journeyhomeB．bigkillersofCaliforbniacondorasC．restplacesforcondorsatnightD．usedtokeepcondorsaway【小题3】AccordingtoParaghaph5,leadpoisoning.A．makescondorstoonervoustoflyB．haslittleeffectoncondors’kidneysC．canhardlybegottenridofformcondors’bloodD．makesitdifferentforcondorstoproducebabybirds【小题4】Thepassageshowsthat.A．theaveragesurvivaltimeofcondorsissatisfactoryB．Rideout’sresearchinterestliesinelectricengineeringC．theeffortstoprotectcondorshavebroughtgoodresultsD．researchershavefoundthefinalanswerstotheproblem