初二物理 液体压强 异形容器问题PPT课件

.,液体压强重难点之异形杯问题,.,产生原因：液体受到重力作用，并且具有流动性公式：P=gh,液体压强,.,好了，废话不多说,上图,.,如下图，在质量不计、底面积相等的甲、乙、丙三个容器中，装入相同高度的同种液体,液体对容器底部的压强P甲P乙P丙液体对容器底部的压力F甲F乙F丙容器对桌面的压强P甲P乙P丙容器对桌面的压力F甲F乙F丙,相同高度同种液体,=,=,=,=,.,如下图，在质量不计、底面积相等的甲、乙、丙三个容器中，装入相同质量的液体,液体对容器底部的压强P甲P乙P丙液体对容器底部的压力F甲F乙F丙容器对桌面的压强P甲P乙P丙容器对桌面的压力F甲F乙F丙,相同质量,=,=,=,=,.,如下图，在质量不计、底面积相等的甲、乙、丙三个容器中，装入相同质量的不同液体并使液面在相同高度处,液体对容器底部的压强P甲P乙P丙液体对容器底部的压力F甲F乙F丙容器对桌面的压强P甲P乙P丙容器对桌面的压力F甲F乙F丙,相同高度相同质量不同液体,=,=,=,=,.,总结一下,先算压强，后算压力,.,1.肯定式：There_+a/an可数名词单数/不可数名词There_+可数名词复数,There_ahandsomemanintheclassroom.There_aneggonhishead.There_someorangejuiceintheglass.There_somelovelygirlsintheclassroom.,.,Thereis_Thereare_,.,2.否定式：Therebe+not+主语+其他There_acomputerinmybedroom.=Thereisnocomputerinmybedroom.There_anystudentsintheclassroom.=Therearenostudentsintheclassroom.,nota/an=no,notany=no,.,3.一般疑问句：一般情况：将be动词提前。含情态动词（如：will），则将情态动词提前。Thereissomemilkintheglass.Isthereanymilkintheglass?杯子里有牛奶吗？肯定回答：Yes,there_.是的，有。否定回答：No,there_.不，没有。Therewillbeapartytomorrowevening._there_apartytomorrowevening?明晚将有一个派对吗？肯定回答：Yes,there_.是的，有。否定回答：No,there_.不，没有。,注意：some疑问变any,.,4.therebe句型中对数量进行提问_对可数名词复数进行提问。e.g.Therearefivebirdsinthetree.树上有5只鸟。_arethereinthebirds?_对不可数名词进行提问。e.g.Thereisalittlewaterinthebottle._isthereinthebottle?,.,练习一下（先熟悉笔记+后做题共7分钟）单选（7道）()1.There_somebooksonthesofa.A.hasB.isC.haveD.are()2._childrenarethereinthepark?Therearetwelvechildreninthepark.A.HowmanyB.HowmuchC.HownumberD.Whatmany()3._thereanyjuiceinyourglass?No,_.A.Are;therearentB.Is;thereisntC.Are;therenotD.Is;therenot()4.There_abigtreenearmyhouselastyear.A.isB.areC.wasD.were,.,()5.Willtherebeabirthdaypartyforyounextweek?Yes,_.A.thereisB.willC.therebeD.therewill()6.There_anyfoodinthekitchen.A.isntB.isC.areD.arent()7.There_twocupsofteaonthetable.A.isB.areC.haveD.has,.,完成句子1.Thereissomesoupinthebowl.（改为否定句）(1)_soupinthebowl.(2)_soupinthebowl.2.Therearefourseasonsinayear.（改为一般疑问句，并作肯定回答）_inayear?Yes,_.3.TherearefivepeopleinLilysfamily.（对划线部分进行提问）_people_inLilysfamily?,.,考点来了,Therebe肯否疑问,Therebe就近原则,.,Therebe是个近视眼,.,若句子中有几个并列主语时，be动词的形式要与离其最近的一个主语在人称和数上保持一致。,就近原则,.,Therebe是个近视眼,.,There_adeskandfifty-fivechairsintheclassroom.A.areB.is,.,There_fifty-fivechairsandadeskintheclassroom.A.areB.is,.,选择正确的be动词There_anappleonthetable.桌子上有一个苹果。There_somewaterinthecup.杯子里有一些水。There_fiveapplesonthetable.桌子上有五个苹果。There_oneboyandtwogirlsintheclassroom.教室里有一个男孩和两个女孩。There_twogirlsandoneboyintheclassroom.教室里有两个女孩和一个男孩,练习一下（共4分钟）,.,单选（4道）()1.Whatsinyourbedroom?There_acomputer,twochairsandabookshelfinmyroom.A.areB.beC.hasD.is()2._sometoysandabookontheshelf.A.ThereareB.ThereisC.TherewasD.Therewere()3._somemilkandaneggonthetable.A.ThereareB.ThereisC.TherewasD.Therewere()4._anorangeandtwoapplesinthebasket.A.ThereareB.ThereisC.TherewasD.Therewere,.,易错点注意！,过去时There_acinemainourcitytwoyearsago.两年前，我们城市有一家电影院。There_manytreesherefiveyearsago.五年前，这里有很多树。,Therebe的时态变化,2.将来时There_anEnglishpartynextSaturday.There_aconcertthisSaturday.,.,考点来了,Therebe肯否疑问,Therebe就近原则,therebe和have的区别,.,Hehassomemoney.,Thereissomemoneyonthetable.,.,therebe表示存在，意为“某地/某时有”经常与地点状语或时间状语连用；Thereisameetingeveryevening.Therearesomelegsintheclassroom.have表示拥有，即“某人有”Ihavearoundface.Mr.Wuhasasquareface.,.,用therebe或have/has填空1.I_agoodfatherandagoodmother.2._aTiaonthedesk.3.He_aniPad.4._abasketballontheplayground.5.She_somedresses.6.They_anicegarden.7.Whatdoyou_?8._areading-roominthebuilding?9.WhatdoesMike_?10._anybooksinthebookcase?,练习一下,.,考点来了,Therebe肯否疑问,Therebe就近原则,therebe和have的区别,.,Letspractice！练习一下,.,单选(10道)（共10分钟）()1.Jack_abigschoolbag._manypencilsinit.A.has;ThereisB.have;ThereareC.has;ThereareD.have;Thereis()2.Arethereanymapsonthewall?_A.Therearesome.B.Yes,thereis.C.Yes,thereisone.D.No,thereare.()3.Howmany_arethereinthepicture?A.womanB.womenC.buyD.milk()4.Therearent_treesnearthehouse.Thereisonlyone.A.anyB.someC.manyD.much()5.There_twobowlsofriceonthetable.A.isB.haveC.hasD.are,.,()5.Arethere_housesneartheriver?Yes,thereare_.A.some,someB.any,someC.any,anyD.some,any()_nocoffeeleftyesterday.A.ItbeingB.TherebeingC.ItwasD.Therewas()7.Therearefew_inthefridgeLetsgoandbuysomepeasandcabbagesAvegetablesBfruitCmeatDeggs()8.Look！Therearesome_onthefloorAchildBwaterCboxesDgirl()9There_afootballgameinourschoolAhasBwillhaveCwillbe()10Thereis_foodhereWellhavetobuysomeAanyBsomeCno,.,完成句子1.Ihavethreecrayonsinmyschoolbag.（用therebe句型改写成同义句）_inmyschoolbag.2.Hisunclehassomenewstory-books.（改为一般疑问句）_hisuncle_newstory-books?3.Thereisawomannearthehouse.（变复数）There_nearthehouse.4.Therearesomebusesnearthehill.（变单数）There_nearthehill.,.,六、when引导的时间状语从句,.,什么是when引导的时间状语从句呢？,.,用when引导的一个句子来表示时间概念，则为时间状语从句。翻译为“当.的时候”