英语试题第I卷第一节阅读理解ATherearetwokindsofchanges—chemicalchangeandphysicalchange.Inachemicalchange,thereisalwaysanewsubstance（物质））formed.Breakingupwaterintohydrogenandoxygenisachemicalchange.Ineachofthechemicalchangeatleastonenewsubstanceisformed.Achangeisnotachemicalchangeifitdoesn’tformanewsubstance.Physicalchangesareverycommon,too.Therearemanyexamples.Youcanmakeaphysicalchangebytearingapieceofpaperintotwo,orbycuttingapieceofironwithlathe(车床).Herepaperisstillpaper,andtheironisstilliron.Anotherwayofmakingphysicalchangeisdissolving(溶解)somethinginwater.Whenyoudissolvesaltinwater,thesaltdisappears.Youmaythinkthatanewsubstancehasbeenformed.Butreallythereisnonewsubstance.Thesaltisstillsalt.Youcanstilltasteit.Sothedissolvingofanythingisaphysicalchange.Whenwaterfreezes,thechangeisalsoaphysicalone.Thewaterchangesfromliquidtosolid,butitisstillthesamesubstance.Thatiswhythefreezingofanythingisaphysicalchange.21.Inaphysicalchange_______isformed.A.anewsubstanceB.nothingnewC.apieceofpaperD.apieceofiron22Thedissolvingofsaltinwateris_______..A.aphysicalchangeB.achemicalchangeC.hydrogenandoxygenD.breakingup23.Wecanseparateachemicalchangefromaphysicaloneby_______..A.thechangeofshapeB.thechangeofcolorC.newly-producedsmokeD.newly-formedsubstancesBLong,longagotherewerealotofdonkeys.Thedonkeysworkedhardeveryday.Theyhadnotimetoplayortorelax,buttheyneverfeltappreciatedfortheworktheydid.Onedaytwodonkeysgotbored.Theywantedtoliveacomfortablelife.Sothedonkeyswenttoseeawiseoldman.Theytoldhimtheirproblem.Thewiseoldmanagreedthattheyworkedtoohard,andhewantedtohelpthedonkeys."Ihaveanidea."hesaid."Whatisyouridea?"askedthedonkeys."Iwillpaintyouandnoonewillknowyouaredonkeys,"saidtheman.Themanwentofftofindsomepaintandhereturnedinjustamatterofminutes.Hehadtwopotsofpaint.Onepotwasfilledwithwhitepaint,andtheotherblackpaint.Theoldmanfirstpaintedthemwhite,andthenpaintedblackstripes(斑纹)overthewhitepaint.Whenhefinished,thedonkeysdidnotlookatalllikedonkeys."Younolon