懂你英语Level4unit2.docx

懂你英语Level4unit2.docx

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懂你英语Level4unit2

Level4unit2part1

Listening

Theearthwasformedbyabout4.6billionyearsago.

Thefirstlifeappearedaboutabillionyearslater.

Thefirstplaintsdidn’tappearuntilaround2billionyearsago.

Untilabout580millionyearsago,lifeformsweresmallandmicroscopic.

Sincethattime,lifehasevolvedintomanydifferenttypesorspecies.

However,scientistsestimatethatmorethan99%ofthemarenowextinct.

-Whendidthefirstplantappearonearth?

–about2billionyearsago.

TherehavebeenseveralextinctioneventsinthehistoryoftheEarth.

Inanextinctionevent,manylifeforms,orspeciesoflife,dieout.

Thecausesofmassextinctioneventsareunsolvedmysteries.

Theseeventsarenotpredictable,andcanhappenatanytime.

Scientiststhinkthatsomeofthemwerestartedbyasteroidimpactsorvolcaniceruptions.

Eventslikethiscanchangetheglobalconditionsthatlifedependson.

-Whathappensinanextinctionevent?

–Manyspeciesoflifebecomeextinct.

Onemajorextinctioneventhappenedabout66millionyearsago.

ThateventmayhavebeenstartedbyalargeasteroidthathittheEarth.

Asaresult,thedinosaursandabouthalfofallspeciesontheplanet,diedout.

WhentheasteroidhittheEarth,itstartedachainofevents.

Achainofeventsisaseriesofeventslinkedtogether,likeachain.

-Whatmayhavecausedtheextinctionofthedinosaurs?

–Anasteroidhittheearthandstartedachainofevents.

Thisparticularchainofeventshappenedoveraperiodofmonthsandyears.

WhentheasteroidhittheEarth,itcausedahugecloudofdusttoentertheatmosphere.

ThiscloudofdustblockedthesunanddarkenedtheEarthformanymonths.

Withoutenoughsunlight,plantsandplant-eatinganimalsquicklydied.

Withthedeathsofsomanyplantsandanimals,thefoodchaincollapsed

Thisledtothedeathsofmanymorespecies.

-Whatcausedthefoodchaintocollapse?

–Thedeathsofmanyplantsandplant-eatinganimals.

Massextinctioneventshaveplayedanimportantpartintheevolutionoflife.

Infact,someextinctioneventshavehelpstoaccelerateevolution.

Forexample,somemammalslivedthroughtheageofthedinosaurs,buttheycouldn’tcompete.

Whenthedinosaurswereremoved,themammalswereabletocompetemoresuccessfully.

Oncetheycouldcompete,mammalsevolvedtohigherstate.

Withoutextinctionevents,perhapswewouldn’tbeheretoday.

-Whatmayacceleratetheevolutionofmammals?

–theextinctionofdinosaurs.

Mammalscouldn’tcompetesuccessfullywiththedinosaurs,sotheirevolutionwasblocked.

Scientistsestimatedthattherehadbeenatleast5massextinctionsinthelast540millionyears.

Theyalsobelievedthatwehaveenteredanewextinctionevent.

Speciesarebecomingextinctatamuchfasterratethanbefore.

Insteadoftheasteroidorvolcaniceruptions,thecurrenteventisaresultofhumanactivities.

Humanactivities,forexample,haveledtoglobalwarming.

-Whatiscausingthecurrentmassextinctionevent?

–humanactivities

-Whatdoscientistsbelievehasalreadystarted?

–anewextinctionevent.

Globalwarmingisaresultofanincreasingincarbongasesinoutatmosphere.

Thesegasestrapheatfromthesun,sotheEarthisgettingwarmer.

Asaresult,sealevelsarerising,andweatherpatternsarechanging.

Inaddition,wehumansaredestroyingthehabitatsofmanyplantsandanimals.

Cuttingdownforests,andpollutingriversdestroysthehabitatsofmanyformsoflife.

-Whyaresealevelsrising?

–Withtheriseintemperature,thepolaricecapsaremelting.

Thereisnolongeranydoubtthatthisishappening.

Speciesoflifearedisappearingatanincreasingrate.

Globaltemperaturesarerisingandweatherpatternsarechanging.

Scientistsarewarningusthatfastactionisnecessarytosaveourfuture.

Ifwedon’tact,wemaygothewayofthedinosaurs.

Thisnewextinctioneventiscausedbyhumans.

Vocabulary

Thebody’scirculatorysystemincludestheheartandbloodvessels.

Theheartpumpsbloodtoallpartsofthebodythroughanetworkofarteriesandveins.

Thedigestivesystembreaksdownandabsorbsfoodintothebody.

Itsuppliestheenergythatthebodyneedsforgrowthandrepair.

Afterdigestion,excessfoodisturnedintowasteandeliminatedfromthebody.

Thenervoussystemincludesthebrain,spinalcord,andnerves.

Thisisyourbody’scontrolsystem.

Itcontrolsyourmusclesandorgans,includingyourcirculatoryanddigestivesystems.

Therespiratorysystemincludesthenoseandlungs.

Itbringsairandoxygenintothebodyandremovescarbondioxide.

Thelungsarewhereoxygenentersthebloodstreamandcarbondioxideisremoved.

Theimmunesystemprotectsthebodyagainstinfectionsanddiseases.

Sneezingandfeverareexamplesofhowtheimmunesystemworks.

Ifaninfectioninvadesthebody,theimmunesystemattacksit.

Thenervoussystemregulatesyourheartbeatanddigestion.

Forsomediseases,theimmunesystemuseswhitebloodcellsandantibodiestoattackit.

Thedigestivesystemiswherefoodisbrokendownandabsorbedintothebody.

Thecontrolleduseoffireallowedpeopletocookfoodandsurviveincolderclimates.

Fireprovidedlightsothatpeoplecouldworkandsocializeforlongerhours.

Withtheinventionofagriculturepeoplecouldgrowfoodandsettleintocommunities.

Bygrowingfood,peoplecouldspendlesstimehuntingandmoretimeforotherthingssuchasart.

Thedomesticationofanimalsallowedpeopletoraiseanduseanimalsforfoodandwork.

Byraisingherdsofanimalsuchassheep,humanshadaregularsupplyofmeatandclothing.

Thestrengthofanimalssuchashorseandoxwasusedforworkingtransportation.

Thedevelopmentoftoolsandmachineshasresultedintomoreefficientmanufactureandconstruction.

Withbettertoolsandmachinesworkcanbedonewithfewerpeopleatmuchlowercost.

Thedevelopmentofscienceandengineeringhasimprovedmanythingsincludingcommunications.

Withunderstandingofelectricity,telephonesandradiosallowpeopletocommunicateoverlongdistances.

Scienceandengineeringbreakthroughsarerapidlychangingthewayweliveourlives.

Scienceandengineeringhavechangedthewaywecommunicatewitheachother.

Theuseofmachineshasreducedthenumberofpeopleneededtomakethings.

Withthedevelopmentofagriculture,peoplehadmoretimeforotheractivities.

Theabilitytoraiseherdsofanimalsgavehumanaregularsupplyofmeatandclothing

Dialogue

M:

Itookavocationlastnight.

W:

Whatareyoutalkingabout?

Wheredidyoutakeyourvocation?

M:

Ididn’tgoanywhere.Ijustspentaneveningwithoutmysmartphone.

W:

Howwasit?

M:

Itwasgreat.Igotarealmagazineandreaditwithnointerruption.

Itwasverypeaceful.

W:

Yes,Ihaven’tdonethatinalongtime.

-Ifsomeoneisinterrupted,theyhaveto…

-stopwhattheyaredoing.

-Whathasn’tshedoneinalongtime?

–Shehasn’tspenttimewithouthersmartphone.

-Whatmadetheeveningdifferent?

–Hedidn’tusehissmartphone.

M:

Youknowwhat?

I’mbeginningtohatesmartphones.

W:

Really?

Butyoucan’tlivewithoutone,right?

M:

Yes,that’stheproblem.Thesethingsarechangingthewaypeoplelive.

-Whatcan’tpeoplelivewithout?

–Peoplecan’tlivewithoutsmartphones.

-Howdoeshefeelaboutsmartphones?

–He’sbeginningtohatethem.

W:

Yes,Ijustsawadocumentaryaboutthat.Ahusbandwascomplainingtohiswifethatshewasspendingtoo

muchtimeonhersmartphone.

-Whathappenedtothecouple?

–Theygotadivorce.

-Whatwasthewifespendingtoomuchtimedoing?

–playingonhersmartphone.

M:

It’sabitironic.Don’tyouthink?

Smartphonesweresupposedtobringpeopletogether,buttheyarepulling

peopleapart.

W:

Yes,you’reright.

M:

Hey,justaminute.I’vegotamessageonmysmartphoneanditcan’twait.

-Whatdotheythinkisironicaboutsmartphones?

–Insteadofbringingpeopletogether,theyarepullingthemapart.

Boss:

Hey,wakeupandgetbacktowork.What’swrongwithyou?

Employee:

I’monmybreak,sir.AndIhaveabadheadache.

Boss:

Well,we’renotpayingyoutosleep.Ifyou’regoingtosleep,sleepsomeplaceelse.

Employee:

Yes,sir.Sorry.Itwon’thappenagain.

Boss:

Youhadbetternot.

-Howdidtheemployeetreatthemanager?

–respectfully.

Employee:

Justaminute.Don’ttalktomelikethat.

Boss:

Whatdidyousay?

Employee:

Youhurtme.Youdon’thavetotreatpeoplelikethat.

Boss:

Well,ifyoudon’tlikeit,Isuggestyouleave.

Employee:

OK,Iwill.I‘vehadenoughofyou.I’llgetajobsomewhereelse.

-Howdoestheemployeefeel?

–angry.

Level4unit2part2

Listening

Thismanisholdingapieceoffruitinhishand.

Thepieceoffruitiseitheranorangeoranapple.

Wecan’tseewhichitisbecausewecan’tseeinsidethebox.

Theprobabilitythatitisanorangeisequaltotheprobabilitythatitisanapple.

Itmaybeanappleanditmaybeanorange.

It’sgottobeoneortheother.

Itcan’tbeanythingelse.

-What’stheprobabilitythatit’sabanana?

–Theprobabilityis0%.

Itmaybeanapplebutitcan’tbeabanana.

Nowlet’slookatitfromtheman’spointofview.

Fromhispointofview,theprobabilitiesaredifferent.

Fromhispointofview,theprobabilitythathehasanorangeis100%or0%.

That’sbecauseheknowswhathehas.

Forhim,thereisnouncertainly.

Ifhehasanorange,theprobabilityis100%.

Ifhedoesn’thaveanorange,theprobabilityis0%.

Heeitherhasit,orhedoesn’t.

-Fromourpointofview,what’stheprobabilitythatit’sanorange?

-50%.

Fromourpointofview,theprobabilitythathehasanorangeis50%.

Fromhispointofview,theprobabilit