Oneevening,Daisysaid,'I'mgoingtobuyapacketofsweets.Doesanyonewantanything?Benny,Daisy’sbrother,said,‘Yes.Canyougetmeapacketofelectricity.Please?’Daisysaid,‘OK,’andwentout.Bennylaughed.‘Ha!Ha!I'vetrickedDaisyatlast.Shedoesn'tevenknowwhatelectricityis.Shethinksthatshecanbuyitinpackets,likesweets!Shewillreallylookfoolish.’Mumsaid,‘Doyouknowwhatelectricityis?’Bennysaid,‘Yes.Electricityflowsthroughawire.Ametermeasurestheamountyouuse,andyougetabillforitmonthly.It’slikewater,inaway.’Unit3教材提前看'That'snotabadexplanation,'saidDad,‘althoughelectricityismuchmoredangerousthanwater.Electricityisagoodservant,butadangerousone.Youmustalwaysbecarefulwithit.Canyoutellmewhatitlookslike?’Bennyscratchedhishead.Dadsaid'Nobody'severseenelectricity.It'sinvisible.Butwecanchangeitintodifferentformsofenergythatwecansee,hearorfeel.Canyouthinkofanexample?Bennysaid,'Light!Thelightinalightbulb.'servantelectricityfoolishwiremetermeasurebillcarefulinvisiblepolitelycontainironPart2:WordsPreviewn.仆人n.电能adj.愚蠢的n.金属丝；金属线n.计量器；计量表v.测量；度量n.账单adj.小心的；谨慎的adj.看不见的；隐形的adj.有礼貌地v.包含；含有n.熨斗Part3:LanguagePoints1.politelypolitely为副词，意为“礼貌地”，常用来修饰动词。Weshouldspeaktotheoldpolitely.拓展：polite为形容词，意为“有礼貌的”。bepolitetosb.意为“对某人有礼貌”。Thestudentsarepolitetotheirteachers.[e.g.]她的女儿对其他人很有礼貌。__________________________________________________12.needneed的用法(1)need作情态动词needdosth./neednotdosth.needn’tdo=don’thavetodo不必做(2)need作实义动词needtodosth./don’tneedtodosth.needsth./don’tneedsth.Youneedn’tworryaboutit=Youdon’tneedtoworryaboutit.Sheneedssomebatteries./Shedoesn’tneedanybatteries.Part3:LanguagePoints[e.g.]我认为你一点也不用着急。__________________________________________________Part3:LanguagePoints3.behavebehave为不及物动词，意为“表现”。Childrenbehavedverybadlyafterlunch.Hebehavedwellinclass.拓展：behavior为behave的名词形式，意为“行为”。Thestudentsfoundthat...
