Unit13ThewaterplanetⅠ.BriefStatementsBasedontheUnitAsweallknow,theearthisanoceanplanetand99%percentofthelivingspaceonearthisintheoceans.Itiswaterthatmakestheoceansuchagreatplacetolivein.Thisunitmainlydealswiththepropertiesofwaterandhowthepropertiesofwatermaketheoceanbecomesoimportant.Welearnthisunittohelpstudentsnotonlyknowaboutthepropertiesofwater,butalsolearnhowtousewaterinagoodway.Besides,welearnthisunittoletstudentsrealizetheimportanceofprotectingwater.Ofcourse,itisnecessaryforstudentstomastertheimportantphrasesandsentencesintheunit.MeanwhileweshouldreviewsomeimportantusageofModalVerbs.Ⅱ.TeachingGoals1.Talkaboutwaterandtheocean.2.Practisecommunicativeskills.3.ReviewModalVerbs.4.Writeanexplanationparagraph.Ⅲ.BackgroundInformation1.WhatLiesundertheBlueWater?Justlikethehouseswelivein,theoceanhasseveral“floors”orlayers.Differentfishliveondifferentlayersandareneighbours,thoughnotalwaysfriendlyones!Theocean’stoplayeristhesunlitzone(透光层).Itgoesdowntoaround200metersbelowwater.Thislayeriswarmandbright.Itisalsohometomostplantsandfish.Manyfishinthislayerarestreamlined,sotheycanquicklyswimfromdangerandcatchfood.Thetwilightzone(弱光层)isthenextlayerandisfromabout200to600metersbelowwater.Almostnoplantsgrowhere.Manyanimalsinthiszoneswimuptothesurfaceatnighttofeed,andmoveintodeeperwatersduringtheday.Theyalsoeateachother,somanyofthemhavesharpteethandverybigmouths.Manyfishinthiszonedon’thaveastreamlinedbodybecausetheylieandwaitforpreytocometothem.Belowthetwilightlayeristhemidnightzone(无光层).Itisfrom600meterstothebottomofthesea.Thewateriscoldandcompletelydark.Noplantsliveherebutmanysmallanimalscan.Manyanimalsinthetwilightandmidnightzonesproducetheirownlights.Theangler-fish(琵琶鱼)isoneofthem.Ithasabeautifullightonitsheadtoattractprey!MaybeyouhaveseenoneofthecoolestfilmsFindingNemo(《海底总动员》).DoyourememberMarlin,Nemo’sfather,“borrowed”lighttohelpDoryread?Thatwasn’taflashlight,itwasafish!Theyalsouselighttofrightenenemiesandto“talk”witheachother.2.Water1Afamilyofsixneedsover20gallonsofwateraday,justforbasicdrinking,cookingandkeepingclean;butonlyoneinthreeoftheworld’shouseholdshasawatersupplyinthehome.Mostothersgettheirwaterfromrivers,lakesspringsorholesintheground,or,intown,fromstand-pipessharedwithhundredsofotherfamilies.Throughouttheworld’spoorestcountrieswomendamagetheirhealthandlosehoursofeverydaycarryinghugecontainersofwater—upto44lbsinweight—oftenfromsourcesseveralmilesaway.Alltoofrequentlytheybringhomesicknessordeath,aswellaswater.Untreatedwater,whichmayhavecomefromamuddyholesharedwithcattle,canbelethal,especiallyforyoungchildren.Tosinkawellorpipewaterfromanaturalspring,andmaintainthesystemafterwards,peopleneedaccesstolandwithawatersource,tocapital,equipmentandtechnicalknow-how.Intownstheymayneedtolobbythelocalwaterauthoritytorepairorextendexistingsystems.Waterisprecious,andaccesstoitgivespower—tolandownerswithwellsontheirland,ortocountrycontrollingmajorinternationalrivers.Thedemandsontheearth’swaterresourcesaregrowingrapidly,partlyasaresultofpopulationgrowth,butevenmorebecauseindustrynowusessuchhugequantities—ittakes100000gallonstoproduceacar.Ⅳ.TeachingTime:FiveperiodsTheFirstPeriodTeachingAims:1.Learnandmasterthenewwordsandtheusefulexpressionsofthispart.Words:cube,sailor,disadvantages,entertainmentPhrases:comeupwith,happentoUsefulexpressions:Thewat...
