现代大学英语听力1unit2听力原文

PAGEPAGE21Objectives:0Understandwhatanimalsarebeingdescribed.Gettoknowmoreaboutanimals.Gettoknowmoreabouthowmanandanimalsco-exist.Catchmainideasandsupportingdetails.0Havepracticeinliaisonandcontraction.1)TheyliveinAfricaandIndia.Theyhavefourlegsandatail.Theyareverybigandverystrong.Theyareintelligent,too.Theyhaveatrunkandsomeofthemhavetusks.Theysometimeslivefor70years.2)TheyliveinAfricaandAsia.Theyarebrown.Theyhavearmsandlegs,buttheydon'thaveatail.Theirarmsareverylongandtheyhavebigears.Theyaregoodclimbers.Theyareveryintelligent,too.3)TheyliveinAfrica.Theyareverytall.Theyhavefourlegs,atailandaverylongneck.Theyeatleavesandtwigs.Theycanrunveryfast.Theyarebrownandwhite.4)Theyliveinverycoldcountries.Theyhavewings,buttheycan'tfly.Theyaregoodswimmers.Theyeatfish.Theyareblueandwhiteorblackandwhite.5)TheyliveinAustralia.Theyareredorgray.Theyhaveshortfromlegs,longbacklegsandaverylongtail.Thebacklegsandthetailareverystrong.Theycanrunveryfast.Thefemalescarrytheiryounginapouch.6)TheyliveinAfrica.Theyhavefourlegsandatail.Theyhaveabeautifulcoatwithblackandwhiteorbrownandwhitestripes.Theyeatgrassandplants.7)Theyliveinverycoldcountries.Theyhavefourlegs.Theyareverybigandverystrong.Theyhaveawhitecoat.Theycanswim.Theyeatsealsandfish.(Length:2min.23sec.)A.Writedownthenameoftheanimalbeingsdescribedineachcase.1)elephants2)chimpanzees3)giraffes4)penguins5)kangaroos6)zebras7)polarbearsB.Completethefollowingsentenceswithwhatyouhearonthetape.1)TheyliveinAfricaandIndia.Theyhavefourlegsandatail.2)Theirarmsareverylongandtheyhavebigears.TipsIncasethestudentsdon'tknowsomeoftheEnglishnamesfortheseanimals,theymaygivethenamesinChinese.AndthengetthempractisesayingtheminEnglish.Alternatively,youcouldelicit/introducesuchanimalnamesaschimpanzee,penguin,zebraandkangaroo.Thefastestanimalonlandisthecheetah.Itcanrunataspeedofabout100kilometresanhour.Thefastestbirdintheworldcanflyat170km/h,andthefastestfishcanswimatmorethan100km/h.Humanbeingsarenotveryfast.Thefastestmanintheworldcanonlyrunatabout40km/h.Manyanimalscanrunfasterthanthis.Butmostanimalsrunonfourlegs.Fourlegsarebetterthantwo,aren'tthey?Whydoweonlyhavetwolegs?Scientistssaythatwearemoreintelligentthanotheranimalsbecausewestandontwolegs,sowecanuseourhandsforotherthings.Wecanpickthingsupwiththem.Wecanusetools.Humanbeingshaveusedtoolsformillionsofyears.Thatiswhyourbrainshavedeveloped.Thatiswhywehavebecomethemostintelligentanimalsintheworld.Inthepastfewyears,wehavemadeallkindsofmachines.Wehavemadecars,ships,aeroplanesandspacecraft.Inthesemachineswecantravelfasterthananyanimal--byland,bysea,orbyair.Wecanevengotothemoon.Nootheranimalhaseverdonethat!(Length:1min.30sec.)A.Answerthefollowingquestions.1)Whatisthefastestanimalonland?Key:Thecheetah.2)Whatisthespeedofthefastestbirds?Key:170km/h.3)Whatisthespeedofthefastestfish?Key:Morethan100km/h.4)Whycanmanyanimalsranfasterthanhumanbeings?Key:Becausemostanimalsrunonfourlegs.5)Whycanhumanbeingstravelfasterthananyanimals?Key:Becausewehavemachines.B.Decidewhetherthestatementsaretrue(T)orfalse(F)accordingtothetape.1)Thefastestmanintheworldcanrunat100km/h.[F]2)Mostanimalsrunontwolegs.[F]3)Wehavebecomethemostintelligentanimalsintheworldbecausewehaveusedtoolsformillionsofyears.[T]A:Youknow,we'restudyingdinosaursinscienceclass.It'sreallyinteresting.B:Oh,yeah?Hey,haveyoulearnedwhythedinosaursdisappeared?A:Well,nooneknowsforsure.B:Ithoughtithadsomethingtodowiththeclimate.Thetemperaturemighthavegottencoolerandkilledthemoff.A:Yeah,that'sonetheory.Anotherideaisthattheymayhaverunoutoffood.B:Uh-huh.Andyouknow,there'sevenatheorythattheycouldhavebeendestroyedbyaliensfromouterspace.A:Thatsoundscrazytome!(Length:48sec.)A.Answerthefollowingquestions.1)Whatarethepossiblereasonswhythedinosaursdisappeared?Key:Climate,lackoffoodandaliensfromouterspacemightberesponsiblefortheirextinction.2)Doesthemanbelieveinthetheoryofalieninvasion?Key:No.B.Fillinthemissingwordswithwhatyourhearonthetape.B:Ithoughtithadsomethingtodowiththeclimate.Thetemperaturemighthavegottencoolerandkilledthemoff.A:Yeah,that'sonetheory.Anotherideaisthattheymayhaverunoutoffood.B:Uh-huh.Andyouknow,there'sevenatheorythattheycouldhavebeendestroyedbyaliensfromouterspace.Todothefirstexercisewell,studentsmaybeencouragedtotakenoteswhilelistening.Getthemtopayattentiontosuchexpressionsas"ithadsomethingtodowith...","anotheridea..."and"there'sevenatheorythat..."Afterdoingtheexercises,dosomeoralworkonthistopicifdesired.Questionlike"Whydoyouthinkdinosaursdisappeared?"canbeasked.Fortheshortestlife,thefirstprizemustgotothemayfly,whichtypicallylivesonlyamatterofafewhoursafteritemergesfromitsshell.Fewmayflieslivetoseethesunriseagain.Thesecreaturesdevotetheirwholelivestoasingledesperatemission:findingamateandproducingyoung.Theydon'tevenhavefunctionalmouthsandstomachs.Theysimplyhavenotimetoeat.Infacttheyhavenotimeforanythingelse.Therecord-holderforthelongestlifemaybetheArcticclam,oneofwhichlivedquietlyunderwaterfor220years.Howeveritdidnothaveanybirthcertificatetoprovethis.Onecouldonlyjudgebyitsgrowthrings.Ifyouinsistonbetterdocumentation,theoldestanimaleverwasprobablyatortoisethatdiedin1918.Ithadbeencapturedalreadyfull-grownin1766,nineyearsbeforetheAmericanRevolutionbegan,anditdied152yearslaterasWorldWarIcametoaclose.(Length:1min.20sec.)Answerthefollowingquestions.1)Whatanimalhastheshortestlife?Forhowlong?Key:Themayfly.Afewhours.2)Whatdomayfliesdointheirlifetime?Key:Theyjustdotwothings:findingamateandproducingyoung3)HowdoweknowthatoneoftheArcticclamslivedfor220years?Key:Wecouldjudgebyitsgrowthrings.4)Howlongwasthetortoisethatdiedin1918keptincaptivity?Key:Itwaskeptfor152years.Everyyearabout17millionanimalsareusedinlaboratoryexperiments.Butinmanycountriestoday,adifficultquestionisbeingasked:Dowehavetherighttouseanimalsinthisway?Peoplewhoareforusinganimalsinresearcharguethattheuseofanimalsinmedicalresearchhasmanypracticalbenefits.Animalresearchhasenabledresearcherstodeveloptreatmentsformanydiseases,suchasheartdiseaseanddepression.Itwouldnothavebeenpossibletodevelopvaccinesfordiseaseslikesmallpoxandpoliowithoutanimalresearch.Everydruganyonetakestodaywastriedfirstonanimals.Futuremedicalresearchisdependentontheuseofanimals.Whichismoreimportant:thelifeofaratorthatofathree-year-oldchild?Medicalresearchisalsoanexcellentwayofusingunwantedanimals.Lastyear,over12millionanimalshadtobekilledinanimalsheltersbecausenoonewantedthemaspets.Howeverthosewhoareagainstitpointoutthatthefactthathumansbenefitcannotbeusedtojustifyusinganimalsinresearchanymorethanitcanbeusedtojustifyexperimentingonotherhumans.Animalssufferalotduringtheseexperiments.Theyareforcedtoliveinsmallcages,andtheymaybeunabletomove.Muchoftheresearchthatiscarriedoutisunnecessaryanyway.Animalshavethesamerightsashumansdo--tobeabletomovefreelyandnottohavepainorfearforcedonthem.Researchersmustfindotherwaysofdoingtheirresearch,usingcellcultureandcomputermodeling.Thereshouldbenoanimalsinresearchlaboratoriesatall.(Length:1min.50sec.)Key:A.Answerthefollowingquestion.Whatisthemainideaofthepassage?Key:Peoplehavedifferentopinionsonusinganimalsforresearch.B.Completethefollowingontlineofthepassage.1)Thecaseforusinganimalsinresearch:a)Everydruganyonetakestodaywastriedfirstonanimals.b)Futuremedicalresearchisdependentontheuseofanimals.c)Medicalresearchisalsoagoodwayofusingunwantedanimals.2)Thecaseagainstusinganimalsinresearch:a)Animalssufferalotduringtheexperiments.b)Muchoftheresearchisunnecessary.c)Animalshavethesamerightsashumansdo.3)Somealternativewaysforscientiststodotheirresearch:a)Usingcellculture.b)Usingcomputermodeling.ExerciseBisdesignedtohelpthestudentsgetanoutlineofthepassage,andtohelpthemunderstandboththemainideaandthesupportingdetails.Itisrecommendedthatthestudentsfirsttakenoteswithoutreferringtotheoutlinegiveninthetextbookandthenfillinthemissinginformationbasedontheirnotes.Ifsomeofthestudentsfinditdifficulttofinishthetask,theymayreadtheoutline,andfillintheblankswhilelistening.VisitorstotheNationalZooinWashingtonD.C.canseethreenewyoungtigers.TherarebabiesThemothertigersatnearbyonthegrassasherbabiesrolled,chasedandbiteachotherplayfully.ThenKorenchyalsojumpedintothegames.Hercubswerebornatthezoofourmonthsago.TheyarecalledMike,EricandChrisy.ThenewyoungtigersattheNationalZooeachweighabout13kilograms.Thefurisdarkorangewithblackstripes.TheyeathorsemeatanddrinkmilkfromKorenchy.KorenchyandherbabiesareSumatrantigers.SumatrantigerscamefromtheIndonesianislandofSumatra.Theyarenowindangerofdisappearingfromtheearth.Fewerthan500ofthesetigersKorenchycametotheNationalZoofromtheJakartaZooinIndonesia.ThegiftwaspartoftheSumatranTigerSpeciesSurvivalProgram.Korenchyhasgivenbirthtolivecubsthreetimes.ThefatherofhernewcubsisRokan,aSumatrantigerwhoarrivedtwoyearsagofromanotherzoo.KorenchyandRokanhadtheirbabiesthenaturalwayinsteadofthescientificmethodoftenusedtoproduceyounganimalsinzoos.AwirefenceseparatesRokanfromhisbabies.ZooworkerswhocareforRokansayhereachesthroughthefencetowashthecubswithhistongue.TheysaythismeansherecognizesMike,EricandChrisyashiscubs.However,zooofficialsarehopingthatRokanwillproducemorecubswithanotherfemaleSumatrantigeratthezoo,sotheydonotwanthimtobecometoointerestedinthisfamily.TheNationalZoohopestokeeptheSumatrantigercubsforatleast18monthsbeforesendingthemtootherzoos.Thatisabouttheagewhenmosttigercubsinthewildleavetheirmothers.TheNationalZoohasplacedcamerasintheSumatrantigers'livingarea,sopeoplewithcomputerscanseethem.Todothis,useyourcomputertofindtheNationalZoo'sWebsiteat/natzoo.(Length:3min.40sec.)Key:A.Answerthefollowingquestions.1)WasthemothertigerbornintheNationalZooaswell?Key:No.2)Whyisthefathertigerseparatedfromhiscubs?Key:Becausezooofficialswanthimtoproducecubswithanotherfemaletiger,sotheydon'twanthimtobecometoointerestedinthisfamily.B.Completethefollowingsentenceswithwhatyouhearonthetape.1)Theyoungtigersarefourmonthsold.2)Eachofthemweighsabout13kilograms.3)Theyeathorsemeatanddrinktheirmother'smilk.4)PeoplewithcomputerscanseethedailylifeofthesetigersbyvisitingtheNationalZoo'sWebsiteat/natzoo.C.Choosethebestanswertoeachofthefollowingquestions.1)HowmanySumatrantigersremainintheworld?(C)a)About60.b)Morethan500.c)Lessthan500.2)Korenchyhasgivenbirthto(C)a)threecubsb)fourcubsc)fiveormorecubs3)After18months,thesecubswillbesent(b)a)tothewildb)tootherzoosc)totheJakartaZooCatsinAmericaAnoldexpressionsays,"Man'sbestfriendishisdog."Today,however,itseemsthatcatshavereplaceddogsasthemostpopularpetsinAmericanhomes.Americanshavemorethan62millionpetdogs.Butevenmorecats--morethan64million--liveinAmericanhomes.Thesepetcatsmayhavelonghairorshorthair.Theyaredifferentcolorsandsizes.Somearecostlyanimalsthattakepartincompetitions.ManymorearecommonAmericanmixturesofseveralkindsofcats.Mosthousecatsliveagoodlife.Theyarenotexpectedtoworkfortheirfood.Instead,theyruletheirhomeslikefurrykingsandqueens.Theywaitfortheirownerstoservethem.Americansareincreasinglyseriousabouttheircats.Theseconcernshavemadethecareofcatsintobigbusiness.Eachyear,catownersbuytonsoffoodespeciallypreparedforcats.Theybuytoysandotherequipment.Theybuyjewelryandclothesforthemselveswithimagesofcatsonthem.Someownersevenburytheirdeadpetsinspecialburialgrounds.Humanshavelovedandrespectedcatsforcenturies.Scientistshaveevidencethatcatsandpeoplelivedtogetheraslongas8,000yearsago.Thesmallhousecatwasonceahighlyhonoredanimal.InancientEgyptforexample,peoplewhokilledacatcouldbepunishedbydeath.EarlyinAmericanhistorycatswerenottreatedasgods,however.TheyprobablyarrivedintheUnitedStateswithsettlersandtradersfromEurope.Thesecatsworked.Theykilledratsandmice.Sometimes,Americansmistreatedtheircats.Duringtheearlydaysofthenation,religiousextremistsbelievedthatsomecatswereworkingforthedevil.Blackcatswereespeciallysuspectedofbeingevil.Later,Americanfamilieswhohadenoughfoodbegantakingcatsintotheirhomes.Peoplecaredforthecatsbecausetheanimalsgavethempleasure.Thecatsthankedpeopleforfeedingthembymakingapurringsound.Thispleasantnoiseusuallymeansacatishappy.Animalexpertsofferseveralreasonswhycatshavebecomesopopularashousepets.Theysaycatsneedlesscarethandogs.Andcatsdonotseemtosufferasmuchasdogsfrombeingaloneiftheownersareaway.Still,millionsofotherpeopledonotlikecatsatall.Theysaydogsarebetterandmorelovingpets.Theysaycatsdonothavemuchfeeling.Theybelievecatsstaywithpeopleonlytobefed.Catownersdefendtheirpetsagainstsuchcriticism.Theysaycatsarejustmuchmoreindependentthandogs.Astudentofanimalmedicineexplainsthesituationthisway:dogsfollowyouaround—theywantyoutotalktothemandplaywiththemalotofthetime.Catslikemorespaceandmoreprivacydoesnotmeantheydonotlovetheirowners.(Lenght:4min.27sec.)A.Answerthefollowingquestions.1)WhichhavebecomemorepopularinAmerica,dogsorcats?Howdoyouknowthat?Key:Catshavebecomemorepopular,becausetherearemorepetcatsinAmericanhomes.2)Howlonghavehumanshadcatsintheirhomes?Key:About8,000years.3)WheredidAmericanhousecatscomefrom?Key:TheyprobablyarrivedintheUnitedStatesfromEurope.4)CatshavebeentreatedwellintheUnitedStatesallalong,haven'tthey?Key:No.B.Fillinthemissingwordsinthesummary.1)Thecareofcatshasbecomeabigbusiness,becausecatowners:a)buytonsoffoodespeciallypreparedforcats.b)buytoysandotherequipment.c)buythingswithimagesofcatsonthem.d)burytheirdeadpetsinspecialburialgrounds.2)Peoplewhoprefercatssaycats:a)givetheirownerspleasure.b)needlesscare.c)sufferlessfrombeingalone.d)aremoreindependent.C.Decidewhetherthestatementsaretrue(T)orfalse(F)accord-in9tothetape.1)Mosthousecatslivedagoodlife.[F]2)EarlyAmericancatsweretreatedlikegods.[F]3)Blackcatswereoncesuspectedworkingforthedevil.[T]4)Catsaretreatedlikefairykingsandqueens.[F]5)Catswantyoutotalktothemalot.[F]Alltheexercisesforthispassagearedesignedtohelpthestudentsgetdetails.InExerciseC,sentence4)maycausesomeproblem.Forsomestudentstheword"furry"maysoundsimilarto"fairy".Makethestudentsawarethatinlisteningcomprehensioncontextisveryimportanttoo."Catsaretreatedlikefairykingsandqueens"simplydoesn'tmakesense,thereforeit'sfalse.LittleStevehasapetrabbit,Bunny.Heplayswithiteverydayafterschool.OnedayhismotherseesthatherlittleboyisholdingBunnybytheears.Fromtimetotimehegivesthepoorrabbitanangryshakeandsays,"Howmuchistwoplustwo?Steve,"sayshismother,"whydoyoutreatyourpoorlittleBunnythatway?""Well,"explainsSteveangrily,"ourteachersaysthatrabbitsmultiplyveryquickly,butthisdummycan'tevenadd."(Length:40sec.)Thisisahumorousstory.Firstdothedictation.Thencallthestudents'attentiontotheword"multiply"whichcanmean"producelargenumbersofoffspring"or"addanumbertoitselfaparticularnumberoftimes".Theboymisunderstood,hencethehumour.Script:Mostmammalsliveonland,butnotallofthem.Millionsofyearsago,somemammalswentbacktotheseaandlivedthere.Thelegsoftheseanimalsdisappeared,andafteralongtimetheylookedlikefish.Theseanimalsbecamewhalesanddolphins.Whalesanddolphinsarestilllikeothermammalsinmanyways.Theyarewarm-bloodedandtheybreatheair.Theyalsohavebigbrains.Thatiswhytheyaremoreintelligentthanfish.Whaleshavethebiggestbrainsintheworld.Theirbrainisbiggerthanthebrainofahumanbeing.(Length:50sec.)Objectives:0Understandwhatanimalsarebeingdescribed.Gettoknowmoreaboutanimals.Gettoknowmoreabouthowmanandanimalsco-exist.Catchmainideasandsupportingdetails.0Havepracticeinliaisonandcontraction.1)TheyliveinAfricaandIndia.Theyhavefourlegsandatail.Theyareverybigandverystrong.Theyareintelligent,too.Theyhaveatrunk（树干；躯干；象鼻）andsomeofthemhavetusks（獠牙）.Theysometimeslivefor70years.2)TheyliveinAfricaandAsia.Theyarebrown.Theyhavearmsandlegs,buttheydon'thaveatail.Theirarmsareverylongandtheyhavebigears.Theyaregoodclimbers.Theyareveryintelligent,too.3)TheyliveinAfrica.Theyareverytall.Theyhavefourlegs,atailandaverylongneck.Theyeatleavesandtwigs（小枝；嫩枝）.Theycanrunveryfast.Theyarebrownandwhite.4)Theyliveinverycoldcountries.Theyhavewings,buttheycan'tfly.Theyaregoodswimmers.Theyeatfish.Theyareblueandwhiteorblackandwhite.5)TheyliveinAustralia.Theyareredorgray.Theyhaveshortfromlegs,longbacklegsandaverylongtail.Thebacklegsandthetailareverystrong.Theycanrunveryfast.Thefemalescarrytheiryounginapouch（小袋；育儿袋）.6)TheyliveinAfrica.Theyhavefourlegsandatail.Theyhaveabeautifulcoatwithblackandwhiteorbrownandwhitestripes（条纹）.Theyeatgrassandplants.7)Theyliveinverycoldcountries.Theyhavefourlegs.Theyareverybigandverystrong.Theyhaveawhitecoat.Theycanswim.Theyeatseals（密封；印章；海豹）andfish.(Length:2min.23sec.)A.Writedownthenameoftheanimalbeingsdescribedineachcase.1)elephants2)chimpanzees([,tʃimpən'zi:])（黑猩猩）3)giraffes（长颈鹿）4)penguins(['peŋɡwin])（企鹅）5)kangaroos（袋鼠）6)zebras7)polarbearsB.Completethefollowingsentenceswithwhatyouhearonthetape.1)TheyliveinAfricaandIndia.Theyhavefourlegsandatail.2)Theirarmsareverylongandtheyhavebigears.TipsIncasethestudentsdon'tknowsomeoftheEnglishnamesfortheseanimals,theymaygivethenamesinChinese.AndthengetthempractisesayingtheminEnglish.Alternatively,youcouldelicit/introducesuchanimalnamesaschimpanzee,penguin,zebraandkangaroo.Thefastestanimalonlandisthecheetah(['tʃi:tə]猎豹).Itcanrunataspeedofabout100kilometresanhour.Thefastestbirdintheworldcanflyat170km/h(尖尾雨燕),andthefastestfishcanswimatmorethan100km/h(旗鱼).Humanbeingsarenotveryfast.Thefastestmanintheworldcanonlyrunatabout40km/h.Manyanimalscanrunfasterthanthis.Butmostanimalsrunonfourlegs.Fourlegsarebetterthantwo,aren'tthey?Whydoweonlyhavetwolegs?Scientistssaythatwearemoreintelligentthanotheranimalsbecausewestandontwolegs,sowecanuseourhandsforotherthings.Wecanpickthingsupwiththem.Wecanusetools.Humanbeingshaveusedtoolsformillionsofyears.Thatiswhyourbrainshavedeveloped.Thatiswhywehavebecomethemostintelligentanimalsintheworld.Inthepastfewyears,wehavemadeallkindsofmachines.Wehavemadecars,ships,aeroplanesandspacecraft.Inthesemachineswecantravelfasterthananyanimal--byland,bysea,orbyair.Wecanevengotothemoon.Nootheranimalhaseverdonethat!(Length:1min.30sec.)A.Answerthefollowingquestions.1)Whatisthefastestanimalonland?Key:Thecheetah.2)Whatisthespeedofthefastestbirds?Key:170km/h.3)Whatisthespeedofthefastestfish?Key:Morethan100km/h.4)Whycanmanyanimalsranfasterthanhumanbeings?Key:Becausemostanimalsrunonfourlegs.5)Whycanhumanbeingstravelfasterthananyanimals?Key:Becausewehavemachines.B.Decidewhetherthestatementsaretrue(T)orfalse(F)accordingtothetape.1)Thefastestmanintheworldcanrunat100km/h.[F]2)Mostanimalsrunontwolegs.[F]3)Wehavebecomethemostintelligentanimalsintheworldbecausewehaveusedtoolsformillionsofyears.[T]A:Youknow,we'restudyingdinosaurs(恐龙)inscienceclass.It'sreallyinteresting.B:Oh,yeah?Hey,haveyoulearnedwhythedinosaursdisappeared?A:Well,nooneknowsforsure(确实；毫无疑问地).B:Ithoughtithadsomethingtodowith(这与…有关)theclimate.Thetemperaturemighthavegottencooler(冷的)andkilledthemoff(消灭,杀光).A:Yeah,that'sonetheory.Anotherideaisthattheymayhaverunoutof(用完，耗尽)food.B:Uh-huh.Andyouknow,there'sevenatheorythattheycouldhavebeendestroyedbyaliens(外星人)fromouterspace.A:Thatsoundscrazytome!(Length:48sec.)A.Answerthefollowingquestions.1)Whatarethepossiblereasonswhythedinosaursdisappeared?Key:Climate,lackoffoodandaliensfromouterspacemightberesponsiblefortheirextinction.2)Doesthemanbelieveinthetheoryofalieninvasion?Key:No.B.Fillinthemissingwordswithwhatyourhearonthetape.B:Ithoughtithadsomethingtodowiththeclimate.Thetemperaturemighthavegottencoolerandkilledthemoff.A:Yeah,that'sonetheory.Anotherideaisthattheymayhaverunoutoffood.B:Uh-huh.Andyouknow,there'sevenatheorythattheycouldhavebeendestroyedbyaliensfromouterspace.Todothefirstexercisewell,studentsmaybeencouragedtotakenoteswhilelistening.Getthemtopayattentiontosuchexpressionsas"ithadsomethingtodowith...","anotheridea..."and"there'sevenatheorythat..."Afterdoingtheexercises,dosomeoralworkonthistopicifdesired.Questionlike"Whydoyouthinkdinosaursdisappeared?"canbeasked.Fortheshortestlife,thefirstprize(一等奖；第一名)mustgotothemayfly(蜉蝣),whichtypically(代表性地,典型地)livesonlyamatterof(大约，左右)afewhoursafteritemergesfromitsshell.Few(很少；几乎没有)mayflieslivetoseethesunriseagain.Thesecreaturesdevotetheirwholelivestoasingledesperate(令人绝望的)mission:findingamate(配偶)andproducingyoung.Theydon'tevenhavefunctional(功能的)mouthsandstomachs.Theysimplyhavenotimetoeat.Infacttheyhavenotimeforanythingelse.Therecord-holder(记录保持者)forthelongestlifemaybetheArcticclam(蛤蜊),oneofwhichlivedquietlyunderwaterfor220years.Howeveritdidnothaveanybirthcertificate(出生证明)toprovethis.Onecouldonlyjudgebyitsgrowthrings(生长轮,年轮).Ifyouinsistonbetterdocumentation(文件材料),theoldestanimaleverwasprobablyatortoisethatdiedin1918.Ithadbeencaptured(捕获)alreadyfull-grown(发育完全的,长足的)in1766,nineyearsbeforetheAmericanRevolution(美国独立战争)began,anditdied152yearslaterasWorldWarIcametoaclose.(Length:1min.20sec.)鹤寿千岁，以极其游；蜉蝣朝生而暮死，而尽其乐(仙鹤的千年寿命，用来尽情遨游；蜉蝣早上出生，傍晚就死了，但也的到它的快乐)淮南王刘安寄蜉蝣于天地，渺沧海于一粟。赤壁赋从冰雪覆盖的北极地区挖掘出来的蛤蜊被证实为世界上最长寿的动物。英国班戈大学的气候研究者们最近从一只蚌蛎类蛤蜊的壳上数到405个年轮。可以推测，当它翩翩年少之时，莎士比亚正在创作他最伟大的剧作，而美洲的第一个英国殖民地才刚刚在维吉尼亚的詹姆斯敦建立。研究小组是在冰岛北海岸外的262英尺（80米）深水中打捞到这只软体动物的。5x405122kjpg800x533366kjpg

Answerthefollowingquestions.1)Whatanimalhastheshortestlife?Forhowlong?Key:Themayfly.Afewhours.2)Whatdomayfliesdointheirlifetime?Key:Theyjustdotwothings:findingamateandproducingyoung3)HowdoweknowthatoneoftheArcticclamslivedfor220years?Key:Wecouldjudgebyitsgrowthrings.4)Howlongwasthetortoisethatdiedin1918keptincaptivity?Key:Itwaskeptfor152years.Everyyearabout17millionanimalsareusedinlaboratoryexperiments.Butinmanycountriestoday,adifficultquestionisbeingasked:Dowehavetherighttouseanimalsinthisway?Peoplewhoareforusinganimalsinresearchargue(主张