Unit 5 Travelling abroad 全国公开课一等奖

Clouds,clouds,cloudsBeforeyoustart(1)and(2)Howmanydifferentkindsofcloudsdoyouknow?Whatdotheylooklikeandwhataretheirnamesinyourlanguage?Canyousometimesseetwoorthreekindsatthesametime?Whatinformationdodifferentkindsofcloudsgiveyouabouttheweather?Reading(1):DescriptionCloudsCloudsoftenlooksoftandfluffy,don'tthey?But,ifyoustoodinacloud,itcertainlywouldn'tfeelsoftandfluffy.Itwouldfeeldamp,asifyouwerestandinginafog.Infactfogisactuallyacloudthatisclosetotheground.Cloudsbringusprecipitation-drizzle,rain,snowandhail.Acloudismadeupofbillionsofwaterdropletsstucktobitsofdustorsalt.Whenthewaterdropletsbecomeheavytheyfallasrain.Ittakesthousandsofthesewaterdropletstoformoneraindropthatisheavyenoughtofalltowardstheground.Highup,theairisverycoldandcloudsareusuallymadeupoftinyiceparticles.Whentheicecrystalsbecomebigger,theyfallassnow.Astheyfallthroughclouds,tinyicecrystalscanalsocollectwaterthatfreezesonthesurfaceoftheicecrystals.Thecrystalsgrowandfalltothegroundashail.Whenyoulookatclouds,youwillnoticethattheyareatdifferentaltitudes.Thesametypeofcloudcanoccuratdifferentaltitudesdependingonwhethertheyareinapolar,temperateortropicalregion.CloudsPolar:altitude(km)Temperate:altitude(km)Tropical:altitude(km)High3-85-136-18Middle2-42-72-8Low0-20-20-2Thethreemaintypesofcloudsarecumuliformclouds,stratiformcloudsoracombinationofthese.Cumuliformcloudslookwoollyandhaveflatbottoms.Stratiformcloudsarelayeredandappearassheetsofcloud.ThenamesofcloudscomefromLatinwordsthatdescribetheircharacteristics.Thewordcumulus(积云)means“heap”socumuluscloudslooklikePilesofrounded，puffyclouds．Thewordstratus(层云)means“spreadout”or“layered”sostratuscloudsarehorizontallayersofcloudsspreadacrossthesky．Thewordcirrus(卷云)means“curlofhair”socirruscloudsarewispylikehairorfeathers．Combinationsofthesenamesareusedtodescribeotherclouds，forexample，cirrocumulus(卷积云)andstratocumulus(层积云)．Ifthewordnimbus(雨云)ornimboisinthename，itmeansthecloudisaraincloud．Ifthewordalto(表示“高”)isinthename．itmeansthecloudsarehigh．(363words／_______minutes)Vocabularyfluffy绒毛状的precipitation降水(量)drizzle毛毛雨，细雨hail冰雹droplet小滴crystal晶体；水晶polar地极的，极地的temperate温带的tropical热带的woolly像羊毛的；卷毛的puffy膨胀的，鼓起的wispy一缕缕的，成束的Exercise1TheadjectivesbelowareusedinReading(1)and(2)todescribeclouds.Findtheminthetexts.Guesswhattheymean.Thencheckyourguessesinyourdictionary.fluffy,woolly,wispy,puffy,lumpy,layered,rounded,rippled,striped,horizontalExercise2Answerthesequestions.1.Howisrainformed?2.Howissnowformed?3.Howishailformed?4.Lookatthetable.Whatisthealtituderangeofcloudsintropicalregions?5.Whatclimaticregioncanhighcloudsbeatanaltitudeoffourkilometres?Exercise3LookatthemeaningoftheLatinwordsinthetext.Thenmatchthecloudnamewiththecorrectdescription.1.cumulonimbus(积雨云)2．cirrostratus(卷层云)3．stratocumulus(层积云)4．nimbostratus(雨层云)5．altocumulus(高积云)a)raincloudsinhorizontallayersb)rounded,puffycloudshighintheskyc)ahorizontallayerofwispy,feather-likecloudsd)ahorizontallayerofroundedcloudse)raincloudsinaheapReading(2)CloudnameTypeDescriptionWeatherHighcloudscirrus(卷云)SWhite,feathery,wispy,madeupoficecrystals.Don'tbringprecipitation.cirrocumulus(卷积云,鱼鳞云)CoLookrippledlikefishscales.Mayprecedethunderstorms.cirrostratus(卷层云)STransparent,whitishcloud,totallyorpartlycoveringthesky.Sometimeswhenthesunorthemoonshinesthroughtheseclouds,weseebrightlycolouredringsaroundthem.Middlecloudsaltocumulus(高积云)CoLooklikewhiteorgrey,puffycottonballs.altostratus(高层云)SGreyorbluish,lightlystriped.Don'tbringprecipitation.nimbostratus(雨层云)SHidethesun,layerofgreycloudsthatdarkenastheirbasesBecomeclosertotheground.Icecrystalsgrowlargeenoughtofallassnow.Thetruerainclouds,bringrainorsnow.Lowcloudsstratus(层云)SLoweststratiformclouds.Looklikegreysheetsspreadacrosssky,blockingoutthesun.Fogsarestratuscloudsthatformonorsinktothesurfaceoftheearth.Don'tbringmuchrainorsnow,morelikelytobringdrizzle.stratocumulus(层积云)CoLumpy-lookingcloud,greyand/orwhitish.Whentheyfilltheskytheyoftenappearinlongheavyridges.Don'tbringprecipitation.cumulus(积云)CLookwoolly,likepilesofcottonballs;theyhaveflatdarkbases.Whensmallormediumandinabluesky,they'refairweatherclouds.Whenbiggeranddarker,rainorsnowisprobablyontheway.Cumulonimbus(积雨云)CFormhugetowersinthesky.Haveflattopsanddarkgreybases.Insidearefiercewinds.Bringthunderstorms.Key:C=cumuliform(积云状的);S=stratiform(层状的);Co=combination(混合状的)Vocabularyrippled呈波纹状的precede在……之前thunderstorm雷暴transparent透明的lumpy多块的；高低不平的ridge脊状突起；山脊tower塔楼，塔fierce猛烈的，狂暴的NotesCottonballs(棉花球)areballsoffluffycottonfromthecottonplantthatpeopleusetocleanorapplylotionstotheskin.Exercise4Readthetableandanswerthequestions.1.Whichcloudsbringprecipitation?2.Whichcloudstellusthatrainmaybeontheway?3.Whichcloudsareacombinationofcumuliformandstratiformclouds?4.Whatisfog?5.Inwhatkindofcloudsmightyouseeringsaroundthemoon?Exercise51.Circlealltheadjectivesinthetablethatdescribetheappearanceofclouds.Usethedictionarytofindthemeaningsofanyyoudon'tknow.2.Canyouthinkofanythingelsethattheseadjectivescoulddescribe?Didyouknow?Aircraftcanformcloudswhenthewaterintheaircraft'sexhaust(喷出气流)condenses(凝结).Thesearecalledcondensationtrailsorcontrails(凝迹)Contrailsusuallydisappearintothesurroundingairbutsometimestheyquicklyfreezeandstayintheskyforalongtimeafterthejethaspassed,Thewindmaystretchthemintolongsheetsofnewcirrusclouds.Keys:Exercise21.Whenthewaterdropletsinthecloudsbecomeheavyenoughtofalltothegrou