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要在一个直径是10米的圆形花坛周围修一条宽1米的小路，这条小路占地面积是 平方米．
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10π
24π
25π
49π
为美化校园学校在教学楼前修了一个直径是10米的圆形花坛围绕花坛有一条2米宽的环形小路这条小路的面积是
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一个圆形花坛的直径是10米围绕花坛修一条宽2米的小路这条小路的面积是
公园里有一个直径是10米的圆形花坛周围有一条1米宽的小路．这条小路的面积是多少平方米
一个直径是10米的圆形花坛周围有一条1米宽的小路．这条小路的面积是多少平方米
一个直径为18米的圆形花坛周围有一条宽1米的小路这条小路的面积是多少平方米
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学校准备在直径10米的圆形花坛的周围修一条宽1米的环形小路你能求出这条小路的面积吗
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10
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有下列实验操作及对实验现象的描述其中错误的是 A．先用蒸馏水润洗pH试纸然后用玻璃棒蘸取少量稀盐酸滴在pH试纸上测定该HCl的pH值． B．酸式滴定管用蒸馏水洗净后先用标准液润洗然后再装入标准液． C．反应FeCl3+3KSCN⇌FeSCN3+3KCl达到平衡后向溶液中加入少量KCl固体溶液颜色变浅． D．CuSO4溶液中滴入少量NaOH得到新制的氢氧化铜然后再滴入少量乙醛加热至沸腾后可检验醛基． E．制取乙酸乙酯时为了使受热均匀一般采用水浴加热．
在浓硝酸和浓氢氧化钠溶液中均不能溶解的单质是
30分Howdareyou!Myangerfinallyburstoutwhenmyson1togotothepianoclassesforthethirdtimethatday.Herolledhiseyesatmewhichmademeeven2.Icompletelylostmy3andscreamedatthetopofmylungsEnough!Youarenotmyboyanymore!Hedidn't4ortalkbacktome.Herespondedin5withalookofhelplessnessthatIhadneverseenbefore.Heusedtocryviolentlyandbegmeto6him.Theinnocenceshininginhisbigeyeswould7thathot﹣temperedbeastinmeawayintheend.8.thistime… Didwhathehaddonereallymakeme9?No.Didsuchangercomeentirelyfromhisimproper10?No.HadIevergivenitachancetolistentoand11him?No.Mydemandingjobmy12houseworkmykid'scryforcompany…allformedaminefield雷区andallthatwasneededto13itupwasafuse导火索.Mysonwasthe14. Therestofthedayhe15anoutdoorwalkarideintheparkandevenhisfavoritegamesandjustwantedtobealone.Icould16thegreatestsorrowandthemosttrueinnocenceinhiseyes.AfteradmittingmyownfaultIheldthistinytremblingcreature17inmyarmstearsswellinginmyeyes. ForthosewhobelieveSticksandstonesmaybreakthebonebut18canneverhurtanyoneIhaveapieceofheartfeltadvice.Donottrythismostpowerfulweapon19thepeopleyoulove.Itis20enoughtocutthedeepestintoasoul. 1A.refused B.requested C.decided D.demanded 2A.calmer B.emptier C.happier D.angrier 3A.breath B.weight C.temper D.thought 4A.cry B.shout C.smile D.respond 5A.doubt B.relief C.silence D.surprise 6A.pardon B.praise C.abandon D.accompany 7A.put B.give C.throw D.drive 8A.Otherwise B.However C.Therefore D.Moreover 9A.satisfied B.puzzled C.moved D.annoyed 10A.advice B.behavior C.words D.argument 11A.hug B.blame C.forgive D.understand 12A.endless B.enough C.important D.meaningful 13A.put B.blow C.heat D.burn 14A.choice B.answer C.victim D.disaster 15A.declined B.shared C.enjoyed D.accepted 16A.retell B.forget C.read D.forecast 17A.rudely B.firmly C.loosely D.casually 18A.voice B.words C.force D.feelings 19A.for B.with C.beyond D.against 20A.hard B.soft C.sharp D.smooth
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一定温度下容器内某一反应中MN的物质的量随反应时间变化的曲线如图下列表述中正确的是
将一定量的镁和铝分别与足量的盐酸反应若放出氢气的质量相等则参加反应的镁和铝的物质的量之比为
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下列物质中能与金属钠反应放出氢气还能与碳酸氢钠溶液反应放出二氧化碳气体的是
下列有机化合物都含有多个官能团 1其中可以看作是酚类的是填入字母编号下同． 21molB可以和molNa作用．
Areyoutrulyhappy?Doyoueverknowwhatitmeanstobehappyandwhatittakestoachievehappiness?1.ThefollowingareafewtipsthatIfollowtocreatehappinessinmylife.※Makeaplanforachievinggoalsthatyoubelievewillmakeyouhappy.Yourmoodswillverylikelyincreaseifyouaregoingaftersomethingyouvalue.※Surroundyourselfwithhappypeople.Itiseasytobegintothinknegativelywhenyouaresurroundedbypeoplewhothinkthatway.2.※Whensomethinggoeswrongtrytofigureoutasolutioninsteadofbeingabsorbedinselfpity.Trulyhappypeopledon'tallowsetbackstoaffecttheirmoodbecausetheyknowthatwithalittlethoughttheycanturnthecircumstancesbacktotheirfavor.※3.Thesefewminuteswillgiveyoutheopportunitytofocusonthepositivethingsinyourlifeandwillleadyoutocontinuoushappiness.※4.Whetheryoutreatyourselftolunchtakealongrelaxingbathorsimplyspendafewextraminutesonyourappearanceyouwillbesubconsciously下意识地puttingyourselfinabettermood.※Findingthehumorinsituationscanalsoleadtohappiness.Findawaytomakelightofasituationthatwouldotherwisemakeyouhappy.※Keepinghealthyisanotherwaytoachievehappiness.5.A.Whatmakesonepersonhappymaybeverydifferentfromwhatmakessomeoneelsehappy.B.Onthecontraryifyouarearoundpeoplewhoarehappytheiremotionalstatewillbeinfectious.C.Beingoverweightornoteatingnutritiousfoodscanhaveanegativeeffectonyourmood.D.Theseareimportantquestionsforanyonewhoisseekinghappinesstoaskthemselves.E.Spendafewminuteseachdaythinkingaboutthethinsthatmakeyouhappy.F.Therearesometipsinlifethatleadtohappiness.G.It'salsoimportanttotakesometimeeachdaytodosomethingniceforyourself.
Todaywebringyouanoldtale.It'sthestoryofthethreelittlepigsandthebigbadwolfthatblewdownahousemadeofstrawandonemadeofsticks.Theonlyhouseleftstandingwastheonemadeofbricks.Nowthereisnewevidencetosuggestthathousesbuiltwithbalesofstrawcanbeverystrong.Theyarealsoveryenvironmental.PeteWalkerisaprofessorattheUniversityofBathinBritain.Heandateamofresearcherstherehavebuiltahousemadeoutofstrawbalesandhempmaterial.Duringthenexttwelvemonthstheteamwillstudytheeffectivenessofthesematerialsinhomebuilding.ProfessorWalkersaystherearemanygoodreasonsforusingstraw.ProfessorWalker'Oneofthebenefitsisit'sarelativelyinexpensiverenewablematerialthat'sreadilyavailable.'Healsoagreesthatstrawtakesincarbondioxideasitgrowsandhelpstheenvironmentinotherways.Soitcanbeseenashavingnoharmfuleffectsontheenvironment.ProfessorWalker'Thestrawbalewallsarerelativelythckandsoallthatstrawprovidesverygoodthermalinsulation.Sowemakebuildingsthatrequireverylittleheatinginthewinterorindeedverylittlecoolinginthesummer.Sotheyrequireverylittleadditionalenergy.'ProfessorWalkersaysthisreduceshomeoperatingexpenses.Italsoreducestheeffectontheenvironment.Hesaysthecurrentinterestinstrawbalehousesisadirectresponsetotheproblemofclimatechange.DavidLanfearownsaneco﹣friendlyhomebuildingserviceintheUnitedStatescalledBaleonBaleConstruction.Hesayshelaughedwhensomefriendsfirsttoldhimabouthousesbuiltofstraw.Butafterdoinghisownresearchhelearnedthatbuildingwithstrawbalesmadealotofsense.Hehasnowhelpedtobuildmorethantenstrawbalehousesandsaysthebuildingmaterialisbecomingmorewidelyaccepted.Tobuildthehouseshefillsawoodframewithtightlypackedbalesofstraw.Nexthecoatsthewallsinsideandoutwithlayersofclayplaster.Hesaysthecommonideasaboutstrawhousescontinueincludingstoriesaboutthethreatoffire.Mr.Lanfearsaysstrawbalehouseshavedonewellwhentestedforfireresistance.Andhesayshisbuildersusethesamebuildingmethodsastraditionalbuilderstokeepoutrain.DavidLanfear'Weusewhatwecallgoodshoesandagoodhatandthatwouldbeasolidfoundationandareallygoodroof.'1What'sDavidLanfear'sattitudetowardsthestrawhousesatlast?A.Ridiculous.B.Approving.C.Defensive.D.Unbelievable.2Whatcanweinferfromthepassage?A.Usingstrawtobuildhousesisdearerthanusingbricks.B.Thehousesbuiltwithbalesofstrawarestrongerthanthosebuiltwithbricks.C.Strawwhichisconvenienttogetismuchcheaperthanthickbricks.D.Housesmadeofbricksarenobetterthanthosemadeofstraw.3Accordingtothepassageweknowthat.A.thereissomeexperienceinbuildingthestrawhousesB.thehousemadeofstrawbalesisthesameasthetraditionaloneC.thehousemadeofstrawbalesisstillunderresearchD.it'suncertainthatthestrawhousecanbeverystrong
I'vecheatedinschoolwhenIthoughtthatIcouldgetawaywithit.I'mnotproudofitandIdon'tusuallyfeelverygoodaboutmyselfafterwardsbutsometimesit'stheonlywaypossibletosurviveinapressurecooker.Myparentsarereallysetonmygettinggoodgrades.Theystudymyreportcardthesamewaytheyexaminethenewspaper'sstockmarketpage.AndtheymakemefeelthatI'vegottoliveuptotheirexpectations.Butoftenit'slikeeachteacheractsasifhisistheonlysubjectwehave.Theythinknothingofpilingonourhomeworkorgivingsurprisequizzes.Sometimeswehavetotaketwoorthreetestsindifferentsubjectsonthesameday.I'dliketoseealotofadultsIknowpreparingforthat.Whenthepressurebecomestoohighsomekidsmayresortto诉诸于cheating.Ifyouhavethreeorfoursubjectstostudyforyou'renotgoingtobeabletodevoteenoughtimetoeachsubjectinordertobewellpreparedforeachclass.Besidesitmaybetheonlywaylefttoliveuptoyourparents'expectationsandcompetewiththetopstudentsintheclass.Everybodyknowsthatifyoucheatit'simportantnottogetcaught.Fewthingscancausemoreofchaos.Oncemyelderbrothergotcaughtcheatingonamathfinal.Myparentsactedasthoughhe'dcommittedafederalcrime.TheassistantprincipalcalledthemtoschoolbutalthoughtheincidentcausedseveralconferencesIdon'tthinkthatanybodyeverreallyunderstoodwhatmybrotherwasgoingthrough.We'rejustsupposedtoperformoutstandinglyaswellasalwaysacthonestlybuthowmanyadultscanactuallyliveuptothestandardstheysetforus?Myfatherhasgottencountlesstrafficticketsforparkinginnoparkingzonesorfornotcomingtoafullstopatstopsigns.Andyou'vealwayshearingaboutpeoplewhodon'tfiletheirincomestaxhonestly.Howaboutallthecorruptioningovernment?Successfuladultsoftenacceptdishonestyinordertoachievetheirbusinessgoals.Arekidstheonlyoneswhoaresupposedtobeperfect?Mostofmyfriendshavecheatedontestsinschoolatonetimeoranother.Thekidswhonevercheatedareusuallyeitherafraidofgettingcaughtorjustdon'tknowhowtodoitsafely.Nobodywantstocheat.Butifit'sachoiceofbeinghonestorofgettingabettergrademostkidswilltryforthelatter.Thatmaysoundwrongbutwedidn'tmaketheruleswe'rejusttryingtogetby.1Whatisthebesttitleofthispassage?A.Everyonecanfightacheat!B.Everyonelikestocheat!C.Cheatingisreasonable!D.Noonewantstocheat!2eauthoroweschildren'scheattothefollowingEXPECT.A.parentsB.childrenC.teacherD.examinations3thefifthparagraphtheauthormainlywantstosay.A.someadultscannotliveuptothestandardstheysetforthechildrenB.kidsarealwayssupposedtobeperfectC.hisfatheralwayscheatsinhislifeD.childrenshouldn'tlearnfromsuccessfuladults4Whichofthefollowingistrueaccordingtothispassage?A.Theauthorthinksitischildren'srighttocheatinschool.B.Mostoftheauthor'sfriendslikecheatingonthetestsinschool.C.Theauthorthinksitwrongtocheatinschool.D.Theauthorshowsapositiveattitudetowardsasurprisequizinschool.
现有两份铝分别放入足量的盐酸和氢氧化钠溶液中放出的氢气在同温同压下的体积比为13则这两份铝消耗的盐酸和氢氧化钠物质的量之比为
10分假如英语课上老师要求同桌之间交换修改作文请你修改你同桌的以下作文文中共有10处语言错误每句中最多有两处.每处错误仅涉及一个单词的增加删除或修改. 增加在缺词处加一个漏字符号/\并在其下面写出该加的词. 删除把多余的词用斜线\划掉. 修改在错的词下划一横线并在该词下面写出修改后的词. 注意1.每处错误及其修改均仅限一词 2.只允许修改10处多者从第11处起不计分. Myfirsttriptothezoowasyearsbeforeduringanelementaryschoolfieldtrip.ItisanactivityIstillrememberedtothisday.ItwasforthefirsttimethatIhadfoundmesoclosetoanimalsliketigersandlions.Iwouldsaythatthetripwaswortheveryminuteoftimespending.Howeversomefeelthatanimalsshouldnotbekeptincagesandshouldratherbeletoutinthewild.Theythinkkeepinganimalincagesshowsthecruelofhumanbeings.AsfarasIconcernedwithoutzoosmanyofuswouldneverhavethechancetoseehowatigerorlionreallylookslike.
是元素周期表的一部分针对表中的①～⑩中元素用元素符号或化学式填空回答以下问题用序号回答问题的不给分 1①～⑩元素中化学性质最稳定的元素是其原子结构示意图为． 2在③～⑦元素中原子半径最大的元素是其在周期表中的位置为． 3①～⑩中元素的最高价氧化物对应的水化物碱性最强的物质电子式为该物质类型属于化合物“共价”或“离子”． 4②⑦和⑩三种元素非金属性由强到弱的顺序是．
有3克镁铝合金完全溶于盐酸后得到标准状况下的氢气3360毫升在所得的溶液中加入足量的浓氨水可得沉淀质量克．
若aAm+和bBn﹣的核外电子排布相同则下列关系中不正确的是
2017年1月15日全国科学技术名词审定委员会联合国家语言文字工作委员会组织化学物理学语言学界专家确认了117号元素Ts中文名称“”tián．关于Ts的叙述错误的是
下列关于药品的使用和保存仪器选用正确的是
8分 YoungAmericansAreLessWealthyThanTheirParents ThecostoflivingintheUnitedStatesisgoingupnoteswriterAlissaQuartz.AsisreportedinNewYorkPostQuartzpointstothecostsofhousingeducationandhealthcareinparticular.AtthesametimeanewstudythereportofwhichiscalledTheFadingAmericanDreamfoundthathalfofAmericansborninthe1980sarefallingbehindtheirparentseconomically. Thesefindingsshowthatmanyyoungeradultsareexperiencingdownwardmobility.Inotherwordstheyarenotdoingaswelleconomicallyastheirparentswereatthesameage.TheideaofdownwardmobilityisespeciallytroublingforAmericanswritesRobertSamuelsoninTheWashingtonPost.HesaysmostU.S.citizensbelievethatovertimetheamountofmoneytheyearnwillriseandlifewillgeteasier. AlissaQuartzwroteabookaboutthefinancialdifficultiesofAmericans.InthebookQuartztellsaboutteacherswhoarestrugglingtopayforregularcosts.OnehighschoolteacherdrivesforridesharingserviceUberatnighttoearnmoremoney.Hecorrectsstudents'papersbetweenriders.Acollegeprofessorturnedtogovernmentassistancetofeedherchildandpayforadoctor.Quartzsaysevenlawyersincreasinglycannotearnanincomethatenablesthemtomeettheirneeds.Theproblemofdecreasingincomesintheirfieldismadeworsebydebttheymayhavefromlawschool. Quartzandtheeconomistswhostudiedtheseissuessaymanythingshaveledtolowerincomesanddownwardmobility.Theeconomicrecessionof2007to2009ispartlytoblametheysay.Moderntechnologyalsoplaysapart.Quartzsaysrobotsthreatentoreducetheearningsofhealthcareworkersreportersandpeoplewhoworkatsupermarketsdrugstoresandtaxpreparationservices.InTheWashingtonPostRobertSamuelsonnotedthatpoorschoolsaweakhousingindustryandtoomanygovernmentrulesarealsotoblame. Withallthesethingsandmorepartlyresponsiblewhatisthesolution?Theseexpertssaytheansweriscomplex.Butallpointtooneissuethatneedstobeexaminedeconomicinequality.QuartzwritesthatwhileAmericaisoneoftherichestcountriesintheworlditalsohasoneofthebiggestdividesbetweenthewealthyandthepoor. TheresearchersinTheFadingAmericanDreamstudymakeasimilarobservation.TheysayraisingGDPwillnotsignificantlyimprovetheeconomicsituationofmostAmericans.AhigherGDPmayhelponlythosewhoarealreadydoingwell.InsteadtheeconomistssaytheUnitedStatescouldtrytorepeatsomethingAmericansborninthe1940sexperienced.Asthosechildrengrewuptheyalmostallbenefitedfromabettereconomy. 1TheauthormentionstworeportsinParagraph1inorderto. A.explaintheresultsoftworesearches B.introducehisopinionsabouttheissue C.attractreaders'attentiontohealthcare D.leadtothetopicofdownwardmobility 2What'sthemainideaofParagraph4? A.Thecausesofdownwardmobility. B.Theinfluencesofgovernmentrules. C.Thenegativeeffectsofmoderntechnology. D.TheresultsofeconomicrecessioninAmerica. 3Theauthorindicatesinthispassagethat. A.raisingGDPwillgreatlyhelpthepoor B.Americaneconomyhasabrightfuture C.youngAmericanswillrepeattheirparents'experience D.it'svitaltonarrowthegapbetweentherichandthepoor 4WecanlearnfromthepassagethatinAmerica. A.peoplemissthegoodolddaysinthe1940s B.peoplearesufferingfromaworseeconomy C.peoplearepessimisticaboutfutureeconomy D.peoplecomplainalotabouteconomicchanges
能量转化率大氧化剂和还原剂可以不断从外部输入电极产物可以不断输出且能代替汽油作为汽车的动力能持续使用的新型电池为
AfterashortvacationwithmyparentsIreturnedtothecountrywhereI'mvolunteering.ThenextdayIwasbackatmydesk.AndIwas1surprisetofindthatthesmilecardsIorderedwhileIwasawayhadarrived.Thoughtsofhowtousekindactstohelpthoseinneedbegandancinginmyhead2mademydayimmediatelylightup.ThefollowingdaysItookasmallpurseandasmilecardwithmewiththeintentionofgivingittosomeonewho3realneededabigsurprise.Marthaisaladyasinglemotheroffour4childwhocleansourofficegivesusteafoodetc.OnedayIfoundherintheofficetouchingherheadinexhaustionassheended5phonecall.AftertalkingwithherIlearnedthatoneofherchildren6sendbackhomefromschoolbecause7non﹣paymentoffeesandthatshehadjustbeenarrangingforthemoney.SoIdecided8helpmyfirsttargetMartha!WhenshewenttogetlunchIleftherthegiftinabagwithhernameasmilecardandabigsmile9drawonthebag.Later10Marthasawmeagainshesaid'Thankyouverymuch!Youmademyday.'
10.7g氯化铵和足量的氢氧化钙混合后充分加热再将所生成的气体完全溶于水后得50mL溶液计算 1可生成标准状况下的氨气多少升． 2所得溶液的物质的量浓度是多少．
8分WhenLinawasawokenbythesoundofthundershewasaloneontheisland.Theairwascoolandbullfrogscroaked.Itwasthatbriefmomentwhenthesummersunhadsetbutthestarshadn'tyetappeared.Linarubbedhereyesandlookedaround. Hello?shecalled.Celia?Marie? Therewasnoresponse. Themoonwasrisingnowsheddinglightontheisland.TheyhadalwayscalleditForgottenIslandbecausenoonebuttheyseemedtorememberitsexistence.Itwasn'tonanyofthemapstheycouldfindandeventheforestrangersdidn'tknowaboutit.Linalovedthattheislandhiddeninaheavily﹣woodedsidestreamoftheriverwasasecretbetweenthethreefriends﹣herCeliaandMarie. ButnowLinawasherealoneanditwasnight.Worsestillitwasherownfault.ComeonLinaletMarierowtheboat.Celiahadsaid.MariewastwoyearsolderthanLinabutshewasahopelessrower.That'swhyLinarefusedandrowedtheboattotheisland.Theargumentthatfollowedtherefusaltooktheusualform.CeliatookMarie'ssideasshealwaysdid.Linahadexplodedandyelledatthemtojustleave.Sotheygotbackintheboatandleft. Aboltoflightningcrossedthedarkenedskyaccompaniedbyadeafeningthunderclap.Thestormwashere.AsthefirstcoldraindropsliddownherneckLina'smindreturnedtohercurrentproblem.Shewasstuckherebyherself.Shejusthopedshedidn'tbecomeasforgottenastheisland.Thethoughtofitsentachill寒意downherback. SuddenlyLinaspottedsomethinginthewater.ItwasaboatandinsideitwereMarieCeliaandMarie'sdadwhowassteeringthroughthefastflowingwaters.AstheboatapproachedtheysawLinawavingandtheworriedexpressionsontheirfacesturnedtorelief. InherexcitementLinajumpedintotheriver.Onlyonceshewasintheicywaterdidsherememberhowfastthewaterwasmoving.Luckilyastrongarmreachedintothewaterandpulledherout.ShesmiledweaklyatMarie'sdadandwithoutawordhuggedCeliaandMarie.Theydidn'tseemtomindbecomingwet. 1Whatcanbeinferredabouttheisland? A.Itisveryneartheocean. B.Itisapopularplaceforboating. C.Itissurroundedbythickforest. D.Ithasneverbeenreachedbyothers. 2WhydidLinagetangry? A.Mariewouldnothelprowtheboat. B.Linawasleftaloneontheisland. C.Mariedidn'tknowhowtorowtheboat. D.CeliasupportedMarieinthedisagreement. 3WhatcausedLinatofeelachill? A.Hershameabouttheunnecessaryargument. B.Thefirstraindropsoftheapproachingstorm. C.Theideathatnoonewouldcometosaveher. D.Thedropintemperatureasthesunwentdown. 4WhopulledLinaoutofthewater? A.Marie'sfather. B.Linaherself. C.Marie. D.Celia.
下列物质中与CH4互为同系物的是
工业上常用铝土矿主要成分为Al2O3SiO2和Fe2O3等杂质为原料制备铝氢化钠铝氢化钠NaAlH4是有机合成的重要还原剂工艺流程如图 已知SiO2在“碱液”中转化为铝硅酸钠Na2Al2SixO8沉淀． 1过量NaOH溶液溶解铝土矿时为了提高浸出率使所有要提取的金属尽量溶解可采取的措施是．任写一种 2写出Al2O3被过量的NaOH溶液溶解的离子方程式． 3操作1和操作2使用的操作方法是． 4一定条件下往铝中通入纯净Cl2反应会生成填写化学式已知该物质是由分子构成不含离子则相邻原子间形成的化学键为键该物质与NaH反应生成NaAlH4和一种与厨房中常用的调味品成分相同的物质反应Ⅰ请写出反应Ⅰ的化学方程式．
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