懂你英語level3-unit-3

1、Unit31Listening自然災(zāi)害和自然災(zāi)害和環(huán)境保境保護(hù)Therearemanyfmsoflivesonearthincludinghumanbeings.Lifeexistsinavarietyofconditions.Somefmsoflivesliveinthewateryenvironmentliketheoceans.Otherfmsoflivescanbefoundinverydryareaslikedesserts.

2、Howeverfanyfmoflivetoexistconditionsmustberight.Whentheconditionsaren’trightthatfmoflivescanextinct.Tobecomeextinctmeanstodieoutcompletely.Conditionsmustberightflifetoexist.Millionsofyearsagotherewerefmsoflivesthatnolong

3、erexist.Whenconditionchangedthisfmoflifediedout.Oneextinctioneventhappenedabout250millionyearsago.Thisisthelargestextinctioneventofalltime.Manyfmsoflivesbecomeextinct.96%ofalllivesintheoceansdiedout.Mostinsectsalsobecame

4、extinct.Thiseventhappenedoveraperiodofseveralmillionyears.Thecausesofthisextinctioneventarestillunknown.Possiblecausesincludelargestvolcaniceruptionsglobalwarming.Somescientistsbelievethattherewereseveralcauses.Theybelie

5、vethataseriesofeventscausedtheextinctions.Scientistsarewkingfbetterunderstwhatreallyhappened.Inmoderntimeswehumanbeingsfacechangingconditions.Fhumanstoliveweneedcleanaircleanwater.Pollutionisnowagrowingproblemaroundthewl

6、d.Pollutionpoisonstheairwaterthatwedependon.Pollutedairmakespeoplesickafraidtogetoutside.Pollutedwaterpoisonsourfoodsupply.Asaresultweneverknowwhichfoodsaresafetoeat.Humanbeingscanbenotliveinapoisonedenvironment.Therefep

7、ollutionisamajthreattoourexistence.Humansneedtemperaturetobeinacomftablerange.Tobeinacomftablerangemeanstobeneithertoohotntoocold.Withglobalwarmingglobaltemperaturesarerising.Asglobaltemperaturesrisethepolaricecapswillme

8、lt.Asthepolaricecapsmeltoceanlevelswillrise.Areasofsomecountrieswillsoonbeunderwater.Peoplewouldbefcedtorelocatedfromfloodedareas.Innatureevensmallchangescansometimeshavelargeeffects.It’sdifficulttopredictwhat’sgoingtoha

9、ppen.Theentireecosystemthatwedependonischanging.Someofthesechangingsareirreversible.Irreversiblechangescannotbeundone.Let’shopethehumansaresmartenoughtoundersthowthewldischanging.Withmeunderstingwemakebetterchoicesaboutw

10、hattodo.Wecanfacethechallengeofthepollutionsglobalwarming.Weneedtodothisbefeit’stoolate.Thisplaofearthisouronlyhomeweneedtoprotectit.Unit31dialogue紀(jì)念日念日DoyouknowwhatdateisittodayWhatdoyoumeanit’sthespecialdayOhsoyoudon’t

11、remember.RememberwhatWhat’sthespecialIt’souranniversary.Westarteddatingayearagotoday.Ohreally.Sry.Justaminutewhatdoyouthinkthisis.Ohit’sanecklace.DoyoulikeitYesIdo.It’slovely.Especiallytheredheart.MayIputitonNoletmedoit.

12、Soyoudidremember.OfcourseIremember.It’sveryspecialfbothofus.Ihavesomethingfyoutoo.YoudoYesbutyouhavetowaituntillater.OhIcan’twait.Tellmewhatisit.CanyouguesswhatitisCouldyougivemeahWewentthere3monthsago.OhyoumeanAlfredo’s

13、.YesareyouexcitedYousaidyoureallylikethefoodthere.Yesthat’strue.Ialsorememberedthedessert.DoyouYesbutlet’snottalkaboutthatnow.let’snowviewinthesurprise.Thatrestaurantlooksnice.Yesbutitlooksexpensive.Let’sgoinlookatthemen

14、u.Wowthemenulooksgreatespeciallythefish.Yesitlooksgoodbutlookatthoseprices.Let’strysomewhereelse.Sometimeit’soktospendalittlemoney.Yesbutthispriceisabittoohigh.Don’tyouthinkYestheyareabithigh.Butdon’tyouthinkitwthLet’sen