新概念英语4课文

1NEWCONCEPTENGLISH(IV)(newversion)2Lesson1FindingFossilmanWecanreadofthingsthathappened5,000yearsagointheNearEast,wherepeoplefirstlearnedtowrite.Buttherearesomepartsoftheworldwhereevennowpeoplecannotwrite.Theonlywaythattheycanpreservetheirhistoryistorecountitassagas--legendshandeddownfromonegenerationofstory-tellerstoanother.Theselegendsareusefulbecausetheycantellussomethingaboutmigrationsofpeoplewholivedlongago,butnonecouldwritedownwhattheydid.AnthropologistswonderedwheretheremoteancestorsofthePolynesianpeoplesnowlivinginthePacificlegendstohelpthemtofindoutwherethefirst'modernmen'camefrom.Fortunately,however,ancientmenmadetoolsofstone,especiallyflint,becausethisiseasiertoshapethanotherkinds.Theymayalsohaveusedwoodandskins,butthesehaverottedaway.Stonedoesnotdecay,andsothetoolsoflongagohaveremainedwheneventhebonesofthemenwhomadethemhavedisappearedwithouttrace.3Lesson2SparethatspiderWhy,youmaywonder,shouldspidersbeourfriends?Becausetheydestroysomanyinsects,andinsectsincludesomeofthegreatestenemiesofthehumanrace.Insectswouldmakeitimpossibleforustoliveintheworld;theywoulddevourallourcropsandkillourflocksandherds,ifitwerenotfortheprotectionwegetfrominsect-eatinganimals.Weowealottothebirdsandbeastswhoeatinsectsbutallofthemputtogetherkillonlyafractionofthenumberdestroyedbyspiders.Moreover,unlikesomeoftheotherinsecteaters,spidersneverdotheleastharmtousorourbelongings.Spidersarenotinsects,asmanypeoplethink,norevennearlyrelatedtothem.Onecantellthedifferencealmostataglanceforaspideralwayshaseightlegsandaninsectnevermorethansix.Howmanyspidersareengagedinthisworkonourbehalf?OneauthorityonspidersmadeacensusofthespidersinagrassfieldinthesouthofEngland,andheestimatedthatthereweremorethan2,250,000inoneacre,thatissomethinglike6,000,000spidersofdifferentkindsonafootballpitch.Spidersarebusyforatleasthalftheyearinkillinginsects.Itisimpossibletomakemorethanthewildestguessathowmanytheykill,buttheyarehungrycreatures,notcontentwithonlythreemealsaday.IthasbeenestimatedthattheweightofalltheinsectsdestroyedbyspidersinBritaininoneyearwouldbegreaterthanthetotalweightofallthehumanbeingsinthecountry.T.H.GILLESPIESparethatSpiderfromTheListener4Lesson3MatterhornmanModernalpiniststrytoclimbmountainsbyaroutewhichwillgivethemgoodsport,andthemoredifficultitis,themorehighlyitisregarded.Inthepioneeringdays,however,thiswasnotthecaseatall.Theearlyclimberswerelookingfortheeasiestwaytothetopbecausethesummitwastheprizetheysought,especiallyifithadneverbeenattainedbefore.Itistruethatduringtheirexplorationstheyoftenfaceddifficultiesanddangersofthemostperilousnature,equippedinamannerwhichwouldmakeamodernclimbershudderatthethought,buttheydidnotgooutoftheirwaytocourtsuchexcitement.Theyhadasingleaim,asolitarygoal--thetop!Itishardforustorealizenowadayshowdifficultitwasforthepioneers.ExceptforoneortwoplacessuchasZermattandChamonix,whichhadrapidlybecomepopular,Alpinevillagestendedtobeimpoverishedsettlementscutofffromcivilizationbythehighmountains.Suchinnsastherewereweregenerallydirtyandflea-ridden;thefoodsimplylocalcheeseaccompaniedbybreadoftentwelvemonthsold,allwasheddownwithcoarsewine.Oftenavalleyboastednoinnatall,andclimbersfoundshelterwherevertheycould--sometimeswiththelocalpriest(whowasusuallyaspoorashisparishioners),sometimeswithshepherdsorcheesemakers.Invariablythebackgroundwasthesame:dirtandpoverty,andveryuncomfortable.Formenaccustomedtoeatingseven-coursedinnersandsleepingbetweenfinelinensheetsathome,thechangetotheAlpsmusthavebeenveryhardindeed.5Lesson4SeeinghandsIntheSovietUnionseveralcaseshavebeenreportedrecentlyofpeoplewhocanreadanddetectcolourswiththeirfingers,andevenseethroughsoliddoorsandwalls.Onecaseconcernsan'eleven-year-oldschoolgirl,VeraPetrova,whohasnormalvisionbutwhocanalsoperceivethingswithdifferentpartsofherskin,andthroughsolidwalls.Thisabilitywasfirstnoticedbyherfather.Onedayshecameintohisofficeandhappenedtoputherhandsonthedoorofalockedsafe.Suddenlysheaskedherfatherwhyhekeptsomanyoldnewspaperslockedawaythere,andevendescribedthewaytheyweredoneupinbundles.Vera'scurioustalentwasbroughttothenoticeofascientificresearchinstituteinthetownofUIyanovsk,nearwhereshelives,andinAprilshewasgivenaseriesoftestsbyaspecialcommissionoftheMinistryofHealthoftheRussianFederalRepublic.Duringthesetestsshewasabletoreadanewspaperthroughanopaquescreenand,strangerstill,bymovingherelbowoverachild'sgameofLottoshewasabletodescribethefiguresandcoloursprintedonit;and,inanotherinstance,wearingstockingsandslippers,tomakeoutwithherfoottheoutlinesandcoloursofapicturehiddenunderacarpet.Otherexperimentsshowedthatherkneesandshouldershadasimilarsensitivity.DuringallthesetestsVerawasblindfold;and,indeed,exceptwhenblindfoldshelackedtheabilitytoperceivethingswithherskin.ltwasalsofoundthatalthoughshecouldperceivethingswithherfingersthisabilityceasedthemomentherhandswerewet.6Lesson5YouthPeoplearealwaystalkingabout'theproblemofyouth'.Ifthereisone—whichItakeleavetodoubt--thenitisolderpeoplewhocreateit,nottheyoungthemselves.Letusgetdowntofundamentalsandagreethattheyoungareafterallhumanbeings--peoplejustliketheirelders.Thereisonlyonedifferencebetweenanoldmanandayoungone:theyoungmanhasagloriousfuturebeforehimandtheoldonehasasplendidfuturebehindhim:andmaybethatiswheretherubis.WhenIwasateenager,IfeltthatIwasjustyounganduncertain--thatIwasanewboyinahugeschool,andIwouldhavebeenverypleasedtoberegardedassomethingsointerestingasaproblem.Foronething,beingaproblemgivesyouacertainidentity,andthatisoneofthethingstheyoungarebusilyengagedinseeking.Ifindyoungpeopleexciting.Theyhaveanairoffreedom,andtheyhavenotadrearycommitmenttomeanambitionsorloveofcomfort.Theyarenotanxioussocialclimbers,andtheyhavenodevotiontomaterialthings.Allthisseemstometolinkthemwithlife,andtheoriginsofthings.It'sasiftheywereinsomesensecosmicbeingsinviolentandlovelycontrastwithussuburbancreatures.AllthatisinmymindwhenImeetayoungperson.Hemaybeconceited,illmannered,presumptuousoffatuous,butIdonotturnforprotectiontodrearyclichésaboutrespectforelders--asifmereagewereareasonforrespect.Iacceptthatweareequals,andIwillarguewithhim,asanequal,ifIthinkheiswrong.7Lesson6ThesportingspiritIamalwaysamazedwhenIhearpeoplesayingthatsportcreatesgoodwillbetweenthenations,andthatifonlythecommonpeoplesoftheworldcouldmeetoneanotheratfootballorcricket,theywouldhavenoinclinationtomeetonthebattlefield.Evenifonedidn'tknowfromconcreteexamples(the1936OlympicGames,forinstance)thatinternationalsportingcontestsleadtoorgiesofhatred,onecoulddeduceitfromgeneralprinciples.Nearlyallthesportspractisednowadaysarecompetitive.Youplaytowin,andthegamehaslittlemeaningunlessyoudoyourutmosttowin.Onthevillagegreen,whereyoupickupsidesandnofeelingoflocalpatriotismisinvolved,itispossibletoplaysimplyforthefunandexercise:butassoonasthequestionofprestigearises,assoonasyoufeelthatyouandsomelargerunitwillbedisgracedifyoulose,themostsavagecombativeinstinctsarearoused.Anyonewhohasplayedeveninaschoolfootballmatchknowsthis.Attheinternationallevelsportisfranklymimicwarfare.Butthesignificantthingisnotthebehaviouroftheplayersbuttheattitudeofthespectators:and,behindthespectators,ofthenations.whoworkthemselvesintofuriesovertheseabsurdcontests,andseriouslybelieve--atanyrateforshortperiods--thatrunning,jumpingandkickingaballaretestsofnationalvirtue.刘晓华8Lesson7BatsNotallsoundsmadebyanimalsserveaslanguage,andwehaveonlytoturntothatextraordinarydiscoveryofecho-locationinbatstoseeacaseinwhichthevoiceplaysastrictlyutilitarianrole.Togetafullappreciationofwhatthismeanswemustturnfirsttosomerecenthumaninventions.Everyoneknowsthatifheshoutsinthevicinityofawalloramountainside,anechowillcomeback.Thefurtheroffthissolidobstructionthelongertimewillelapseforthereturnoftheecho.Asoundmadebytappingonthehullofashipwillbereflectedfromtheseabottom,andbymeasuringthetimeintervalbetweenthetapsandthereceiptoftheechoesthedepthoftheseaatthatpointcanbecalculated.Sowasborntheecho-soundingapparatus,nowingeneraluseinships.Everysolidobjectwillreflectasound,varyingaccordingtothesizeandnatureoftheobject.Ashoaloffishwilldothis.Soitisacomparativelysimplestepfromlocatingtheseabottomtolocatingashoaloffish.Withexperience,andwithimprovedapparatus,itisnowpossiblenotonlytolocateashoalbuttotellifitisherring,cod,orotherwell-knownfish,bythepatternofitsecho.Afewyearsagoitwasfoundthatcertainbatsemitsqueaksandbyreceivingtheechoestheycouldlocateandsteerclearofobstacles--orlocateflyinginsectsonwhichtheyfeed.Thisecho-locationinbatsisoftencomparedwithradar,theprincipleofwhichissimilar.刘晓华9*Lesson8TradingstandardsChickensslaughteredintheUnitedStates,claimofficialsinBrussels,arenotfittograceEuropeantables.No,saytheAmericans:ourfowlarefine,wesimplycleantheminadifferentway.Thesedays,itisdifferencesinnationalregulations,farmorethantariffs,thatputsandinthewheelsoftradebetweenrichcountries.Itisnotjustfarmerswhoarecomplaining.AnelectricrazorthatmeetstheEuropeanUnion’ssafetystandardsmustbeapprovedbyAmericantestersbeforeitcanbesoldintheUnitedStates,andanAmerican-madedialysismachineneedstheEU’sokaybeforeithitsthemarketinEurope.Asithappens,arazorthatissafeinEuropeisunlikelytoelectrocuteAmericans.So,askbusinessesonbothsidesoftheAtlantic,whyhavetwolotsoftestswhereonewoulddo?Politiciansagree,inprinciple,soAmericaandtheEUhavebeentryingtoreachadealwhichwouldeliminatetheneedtodouble-testmanyproducts.TheyhopetofinishintimeforatradesummitbetweenAmericaandEUonMay28th.Althoughnegotiatorsareoptimistic,thedetailsarecomplexenoughthattheymaybehard-pressedtogetadealatall.Why?Onedifficultyistoconstructtheagreements.TheAmericanswouldhappilyreachoneaccordonstandardsformedicaldevicesandthenhammeroutdifferentpactscovering,say,electronicgoodsanddrugmanufacturing.TheEU-followingfinecontinentaltraditions—wantsagreementongeneralprinciples,whichcouldbeappliedtomanytypesofproductsandhaveextendedtoothercountries.刘晓华10Lesson9RoyalespionageAlfredtheGreatactedashisownspy,visitingDanishcampsdisguisedasaminstrel.Inthosedayswanderingminstrelswerewelcomeeverywhere.Theywerenotfightingmen,andtheirharpwastheirpassport.Alfredhadlearnedmanyoftheirballadsinhisyouth,andcouldvaryhisprogrammewithacrobatictricksandsimpleconjuring.WhileAlfred'slittlearmyslowlybegantogatheratAthelney,thekinghimselfsetouttopenetratethecampofGuthrum,thecommanderoftheDanishinvaders.ThesehadsettleddownforthewinteratChippenham:thitherAlfredwent.Henoticedatoncethatdisciplinewasslack:theDaneshadtheselfconfidenceofconquerors,andtheirsecurityprecautionswerecasual.Theylivedwell,ontheproceedsofraidsonneighbouringregions.Theretheycollectedwomenaswellasfoodanddrink,andalifeofeasehadmadethemsoft.AlfredstayedinthecampaweekbeforehereturnedtoAthelney.TheforcethereassembledwastrivialcomparedwiththeDanishhorde.ButAlfredhaddeducedthattheDaneswerenolongerfitforprolongedbattle:andthattheircommissariathadnoorganization,butdependedonirregularraids.So,facedwiththeDanishadvance,Alfreddidnotriskopenbattlebutharriedtheenemy.Hewasconstantlyonthemove,drawingtheDanesafterhim.Hispatrolshaltedtheraidingparties:hungerassailedtheDanisharmy.NowAlfredbeganalongseriesofskirmishes--andwithinamonththeDaneshadsurrendered.Theepisodecouldreasonablyserveasauniqueepicofroyalespionage!刘晓华11*Lesson10SiliconvalleyTechnologytrendsmaypushSiliconValleybacktothefuture.CarverMead,apioneerinintegratedcircuitsandaprofessorofcomputerscienceattheCaliforniaInstituteofTechnology,notestherearenowworkstationsthatenableengineerstodesign,testandproducechipsrightontheirdesks,muchthewayaneditorcreatesanewsletteronaMacintosh.Asthetimeandcostofmakingachipdriptoafewdaysandafewhundreddollars,engineersmaysoonbefreetolettheirimaginationssoarwithoutbeingpenalizedbyexpensivefailures.Meadpredictsthatinventorswillbeabletoperfectpowerfulcustomizedchipsoveraweekendattheoffice—spawninganewgenerationofgaragestart-upsandgivingtheU.S.ajumponitsforeignrivalsingettingnewproductstomarketfast.‘We’vegotmoregarageswithsmartpeople,’Meadobserves.‘Wereallythriveonanarchy.’AndonAsians.Already,orientalsandAsianAmericansconstitutethemajorityoftheengineeringstaffsatmanyValleyfirms.AndChinese,Korean,FilipinoandIndianengineersaregraduatingindrovesfromCalifornia’scolleges.Astheheadsofnext-generationstart-ups,theseAsianinnovatorscandrawoncustomsandlanguagestoforgetighterlinkswithcrucialPacificRimmarket.Forinstance,AlexAu,aStanfordPh.D.fromHongKong,hassetupaTaiwanfactorytochallengeJapan’snearlockonthememory-chipmarket.India-bornN.DamodarReddy’stinyCaliforniacompanyreopenedanAT&TchipplantinKansasCitylastspringwithfinancingfromthestateofMissouri.Beforeitbecomesaretirementvillage,SiliconValleymayproveaclassroomforbuildingaglobalbusiness.刘晓华12Lesson11HowtogrowoldSomeoldpeopleareoppressedbythefearofdeath.Intheyoungthereisajustificationforthisfeeling.Youngmenwhohavereasontofearthattheywillbekilledinbattlemayjustifiablyfeelbitterinthethoughtthattheyhavebeencheatedofthebestthingsthatlifehastooffer.Butinanoldmanwhohasknownhumanjoysandsorrows,andhasachievedwhateverworkitwasinhimtodo,thefearofdeathissomewhatabjectandignoble.Thebestwaytoovercomeit-soatleastitseemstomeistomakeyourinterestsgraduallywiderandmoreimpersonal,untilbitbybitthewallsoftheegorecede,andyourlifebecomesincreasinglymergedintheuniversallife.Anindividualhumanexistenceshouldbelikeariver--smallatfirst,narrowlycontainedwithinitsbanks,andrushingpassionatelypastbouldersandoverwaterfalls.Graduallytherivergrowswider,thebanksrecede,thewatersflowmorequietly,andintheend,withoutanyvisiblebreak,theybecomemergedinthesea,andpainlesslylosetheirindividualbeing.Themanwho,inoldage,canseehislifeinthisway,willnotsufferfromthefearofdeath,sincethethingshecaresforwillcontinue.Andit,withthedecayofvitality,wearinessincreases,thethoughtofrestwillbenotunwelcome.Ishouldwishtodiewhilestillatwork,knowingthatotherswillcarryonwhatIcannolongerdo,andcontentinthethoughtthatwhatwaspossiblehasbeendone.刘晓华13Lesson12BanksandtheircustomersWhenanyoneopensacurrentaccountatabank,heislendingthebankmoney,repaymentofwhichhemaydemandatanytime,eitherincashorbydrawingachequeinfavourofanotherperson.Primarily,thebanker-customerrelationshipisthatofdebtorandcreditor--whoiswhichdependingonwhetherthecustomer'saccountisincreditorisoverdrawn.But,inadditiontothatbasicallysimpleconcept,thebankanditscustomerowealargenumberofobligationstooneanother.Manyoftheseobligationscangiverisetoproblemsandcomplicationsbutabankcustomer,unlike,say,abuyerofgoods,cannotcomplainthatthelawisloadedagainsthim.Thebankmustobeyitscustomer'sinstructions,andnotthoseofanyoneelse.When,forexample,acustomerfirstopensanaccount,heinstructsthebanktodebithisaccountonlyinrespectofchequesdrawnbyhimself.Hegivesthebankspecimensofhissignature,andthereisaveryfirmrulethatthebankhasnorightorauthoritytopayoutacustomer'smoneyonachequeonwhichitscustomer'ssignaturehasbeenforged.Itmakesnodifferencethattheforgerymayhavebeenaveryskilfulone:thebankmustrecognizeitscustomer'ssignature.Forthisreasonthereisnorisktothecustomerinthemodernpractice,adoptedbysomebanks,ofprintingthecustomer'snameonhischeques.Ifthisfacilitatesforgeryitisthebankwhichwilllose,notthecustomer.刘晓华14Lesson13ThesearchforoilThedeepestholesofallaremadeforoil,andtheygodowntoasmuchas25,000feet.Butwedonotneedtosendmendowntogettheoilout,aswemustwithothermineraldeposits.Theholesareonlyborings,lessthanafootindiameter.Myparticularexperienceislargelyinoil,andthesearchforoilhasdonemoretoimprovedeepdrillingthananyotherminingactivity.Whenithasbeendecidedwherewearegoingtodrill,weputupatthesurfaceanoilderrick.Ithastobetallbecauseitislikeagiantblockandtackle,andwehavetolowerintothegroundandhauloutofthe.groundgreatlengthsofdrillpipewhicharerotatedbyanengineatthetopandarefittedwithacuttingbitatthebottom.Thegeologistneedstoknowwhatrocksthedrillhasreached,soeverysooftenasampleisobtainedwithacoringbit.Itcutsacleancylinderofrock,fromwhichcanbeseenhestratathedrillhasbeencuttingthrough.Oncewegetdowntotheoil,itusuallyflowstothesurfacebecausegreatpressure,eitherfromgasorwater,ispushingit.Thispressuremustbeundercontrol,andwecontrolitbymeansofthemudwhichwecirculatedownthedrillpipe.Weendeavourtoavoidtheold,romanticideaofagusher,whichwastesoilandgas.Wewantittostaydowntheholeuntilwecanleaditoffinacontrolledmanner.刘晓华15*Lesson14TheButterflyEffectBeyondtwoorthreedays,theworld’sbestweatherforecastsarespeculative,andbeyondsixorseventheyareworthless.TheButterflyEffectisthereason.Forsmallpiecesofweather—andtoaglobalforecaster,smallcanmeanthunderstormsandblizzards–anypredictiondeterioratesrapidly.Errorsanduncertaintiesmultiply,cascadingupwardthroughachainofturbulentfeatures,fromdustdevilsandsquallsuptocontinent-sizeeddiesthatonlysatellitescansee.Themodernweathermodelsworkwithagridofpointsoftheorderofsixtymilesapart,andevenso,somestartingdatahastobeguessed,sincegroundstationsandsatellitescannotseeeverywhere.Butsupposetheearthcouldbecoveredwithsensorsspacedonefootapart,risingatone-footintervalsallthewaytototopoftheatmosphere.Supposeeverysensorgivesperfectlyaccuratereadingsoftemperature,pressure,humidity,andanyotherquantityameteorologistwouldwant.Preciselyatnoonaninfinitelypowerfulcomputertakesallthedataandcalculateswhatwillhappenateachpointat12.01,then12.02,then12.03….ThecomputerwillstillbeunabletopredictwhetherPrinceton,onemonthaway.Atnoonthespacesbetweenthesensorswillhidefluctuationsthatthecomputerwillnotknowabout,tinydeviationsfromtheaverage.By1.201,thosefluctuationswillalreadyhavecreatedsmallerrorsonefootaway.Soontheerrorswillhavemultipliedtotheten-footscale,andsoonuptothesizeoftheglobe.刘晓华16Lesson15SecrecyinindustryTwofactorsweighheavilyagainsttheeffectivenessofscientificinindustry.Oneisthegeneralatmosphereofsecrecyinwhichitiscarriedout,theotherthelackoffreedomoftheindividualresearchworker.Insofarasanyinquiryisasecretone,itnaturallylimitsallthoseengagedincarryingitoutfromeffectivecontactwiththeirfellowscientistseitherinothercountriesorinuniversities,oreven,oftenenough,inotherdepartmentsofthesamefirm.Thedegreeofsecrecynaturallyvariesconsiderably.Someofthebiggerfirmsareengagedinresearcheswhichareofsuchgeneralandfundamentalnaturethatitisapositiveadvantagetothemnottokeepthemsecret.Yetagreatmanyprocessesdependingonsuchresearcharesoughtforwithcompletesecrecyuntilthestageatwhichpatentscanbetakenout.Evenmoreprocessesareneverpatentedatallbutkeptassecretprocesses.Thisappliesparticularlytochemicalindustries,wherechancediscoveriesplayamuchlargerpartthantheydoinphysicalandmechanicalindustries.Sometimesthesecrecygoestosuchanextentthatthewholenatureoftheresearchcannotbementioned.Manyfirms,forinstance,havegreatdifficultyinobtainingtechnicalorscientificbooksfromlibrariesbecausetheyareunwillingtohavetheirnamesenteredashavingtakenoutsuchandsuchabookforfeartheagentsofotherfirmsshouldbeabletotracethekindofresearchtheyarelikelytobeundertaking.刘晓华17Lesson16ThemoderncityIntheorganizationofindustriallifetheinfluenceofthefactoryuponthephysiologicalandmentalstateoftheworkershasbeencompletelyneglected.Modernindustryisbasedontheconceptionofthemaximumproductionatlowestcost,inorderthatanindividualoragroupofindividualsmayearnasmuchmoneyaspossible.Ithasexpandedwithoutanyideaofthetruenatureofthehumanbeingswhorunthemachines,andwithoutgivinganyconsiderationtotheeffectsproducedontheindividualsandontheirdescendantsbytheartificialmodeofexistenceimposedbythefactory.Thegreatcitieshavebeenbuiltwithnoregardforus.Theshapeanddimensionsoftheskyscrapersdependentirelyonthenecessityofobtainingthemaximumincomepersquarefootofground,andofofferingtothetenantsofficesandapartmentsthatpleasethem.Thiscausedtheconstructionofgiganticbuildingswheretoolargemassesofhumanbeingsarecrowdedtogether.Civilizedmenlikesuchawayofliving.Whiletheyenjoythecomfortandbanalluxuryoftheirdwelling,theydonotrealizethattheyaredeprivedofthenecessitiesoflife.Themoderncityconsistsofmonstrousedificesandofdark,narrowstreetsfullofpetrolfumes,coaldust,andtoxicgases,tornbythenoiseofthetaxi-cabs,lorriesandbuses,andthrongedceaselesslybygreatcrowds.Obviously,ithasnobeenplannedforthegoodofitsinhabitants.刘晓华18Lesson17Aman-madediseaseIntheearlydaysofthesettlementofAustralia,enterprisingsettlersunwiselyintroducedtheEuropeanrabbit.ThisrabbithadnonaturalenemiesintheAntipodes,sothatitmultipliedwiththatpromiscuousabandoncharacteristicofrabbits.Itoverranawholecontinent.Itcauseddevastationbyburrowingandbydevouringtheherbagewhichmighthavemaintainedmillionsofsheepandcattle.Scientistsdiscoveredthatthisparticularvarietyofrabbit(andapparentlynootheranimal)wassusceptibletoafatalvirusdisease,myxomatosis.Byinfectinganimalsandlettingthemlooseintheburrows,localepidemicsofthisdiseasecouldbecreated.Lateritwasfoundthattherewasatypeofmosquitowhichactedasthecarrierofthisdiseaseandpasseditontotherabbits.Sowhiletherestoftheworldwastryingtogetridofmosquitoes,Australiawasencouragingthisone.Iteffectivelyspreadthediseasealloverthecontinentanddrasticallyreducedtherabbitpopulation.ltlaterbecameapparentthatrabbitsweredevelopingadegreeofresistancetothisdisease,sothattherabbitpopulationwasunlikelytobecompletelyexterminated.Therewerehopes,however,thattheproblemoftherabbitwouldbecomemanageable.Ironically,Europe,whichhadbequeathedtherabbitasapesttoAustraliaacquiredthisman-madediseaseasapestilence.AFrenchphysiciandecidedtogetridofthewildrabbitsonhisownestateandintroducedmyxomatosis.Itdidnot,however,remainwithintheconfinesofhisestate.ItspreadthroughFrancewherewildrabbitsarenotgenerallyregardedasapestbutasasportandausefulfoodsupply,anditspreadtoBritainwherewildrabbitsareregardedasapestbutwheredomesticatedrabbits,equallysusceptibletothedisease,arethebasisofaprofitablefurindustry.ThequestionbecameoneofwhetherMancouldcontrolthediseasehehadinvented.刘晓华19Lesson18PorpoisesTherehaslongbeenasuperstitionamongmarinersthatporpoiseswillsavedrowningmenbypushingthemtothesurface,orprotectthemfromsharksbysurroundingthemindefensiveformation.MarineStudiobiologistshavepointedoutthat,howeverintelligenttheymaybe,itisprobablyamistaketocreditdolphinswithanymotiveoflife-saving.Ontheoccasionswhentheyhavepushedtoshoreanunconscioushumanbeingtheyhavemuchmorelikelydoneitoutofcuriosityorforsport,asinridingthebowwavesofaship.In1928someporpoiseswerephotographedworkinglikebeaverstopushashoreawaterloggedmattress.If,ashasbeenreported,theyhaveprotectedhumansfromsharks,itmayhavebeenbecausecuriosityattractedthemandbecausethescentofapossiblemealattractedthesharks.Porpoisesandsharksarenaturalenemies.Itispossiblethatuponsuchanoccasionabattleensued,withthesharksbeingdrivenawayorkilled.Whetheritbebird,fishorbeast,theporpoiseisintriguedwithanythingthatisalive.Theyareconstantlyaftertheturtles,theFerdinandsofmarinelife,whopeacefullysubmittoallsortsofindignities.Oneyoungcalfespeciallyenjoyedraisingaturtletothesurfacewithhissnoutandthenshovinghimacrossthetanklikeanaquaplane.Almostanydayayoungporpoisemaybeseen