SectionⅠIntroduction&ReadingandVocabularyStepOne：WarmingupDoyoulikedoingscientificexperiments?Whatshouldyoupayattentiontowhenyouarecarryingoutanexperimentinalab?________________________________________________________________________________________________________________________________________________答案：Carryingoutanexperimentinalabisverydangerous.Youmustbecarefulanddotheexperimentunderyourteacher’sguidance.StepTwo：FastreadingReadthetwopassages(P44－45)quicklyandanswerthefollowingquestions.1．Whatshouldweknowwhenweusemetals?________________________________________________________________________答案：Weshouldknowhowmetalsreactwithdifferentsubstances.2．Whatwillhappentocopperwhenitiskeptinwater?________________________________________________________________________答案：Noreaction/Nothing.3．Whyisoiladdedtothewater?________________________________________________________________________答案：Tokeepairoutofthewater.4．Whatistheuseofthecottonwoolinthetesttube?________________________________________________________________________答案：Keepingairdry.StepThree：CarefulreadingReadthetext(P44－45)carefullyandchoosethebestanswers.1．Whichofthefollowingmetalsreactsmostwithwater?A．Copper.B．Iron.C．Aluminium.D．Sodium.答案：D2．AccordingtoPassageA，whichofthefollowingreactsmosteasilywhenitisheatedinoxygen?A．Aluminium.B．Iron.C．Steel.D．Copper.答案：A3．Wecanknowfromtheexperiment________.A．howironrustswithoilB．ironisquiteeasytorustC．howwecanpreventironfromrustingD．howironreactswithalltheothersubstances答案：C4．Ifsomecleanironnailsarekeptinawetplaceforaweek，thenailswill________.A．rustB．notrustC．formanoxideD．keeptheplacedry答案：A5．Thispassagemainlytalksabout________.A．allkindsofmetalsB．whatkindofmetalreactsmostC．thedifferentreactionsofmetalsD．howmetalsreact答案：CStepFour：SummaryDifferentmetalshavedifferentuses.Whenweusemetals，itisimportanttoknowhowtheyreactwithdifferent1.____________.The2.____________ofmetalswiththesesubstancescanbeputinorder.Fromthetable，wecanfindpotassiumreactsthemostwithoxygenandwaterwhilecopper3.____________reactwithwater.Whenweheatcalciuminoxygen，itburnsto4.____________anoxide.Tofindoutifironrustsindryair，inair-freewaterandin5.____________water.Let’sdoasimplescientificexperiment.Weneeddifferentpiecesof6.____________，whicharecleanironnails，testtubes，atesttubeholder，somecottonwool，oilandaBunsenburner.Well，first，putsomeironnailsatthe7.____________ofatesttube.Thenpushsomecottonwooldownthetube.Next，leavethetubeforoneweek.Afteroneweek，thenailshavenot8.____________.Itshowsthatirondoesn’trustwhentheairisdry.Inthesecondpartoftheexperiment，youmustboilthewatertomakesurethereisnoairinit.Youaddsomeoiltothewaterbecausethis9.____________airoutofit.Italsoshowsthatirondoesnotrustinwaterwithoutairinit.10.____________，thenailsrustinthetubewithordinarywaterinthethirdpartoftheexperiment.Thatishowironreactswithairandwithwater.答案：1.substances2.reaction3.doesn’t4.form5．ordinary6.equipment7.bottom8.rusted9.keeps10．Howeverexpandv．膨胀；扩大，扩张(课文原句P41)Whenyouheatametal，itexpands.当你加热一种金属的时候，它会膨胀。①Studentnumbersareexpandingrapidly.学生人数在迅速增加。②Airexpandswhenheated.空气受热膨胀。③Thewriterexpandedhisshortnovelintoalongone.那位作者把他的短篇小说扩展为长篇。④Hiscompanyexpandedintoabigone.他的公司扩...
