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下列物质属于纯净物的是（ ）
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下列物质中属于纯净物的是
纯净的空气
水银
稀盐酸
不锈钢
下列物质中属于纯净物的是
胆矾
水泥
纯净的盐酸
普通玻璃
下列物质属于纯净物的是
纯净的空气
稀硫酸
铜绿
氩气
下列物质中属于纯净物的是
冰水混合物
纯净的盐酸
洁净的空气
CuSO
4
溶液
下列物质属于纯净物的是属于混合物的是①纯净水②二氧化碳③正在加热的高锰酸钾④液态空气
下列各组物质中从物质分类的角度看后者从属于前者的是
纯净物、混合物
金属、非金属
纯净物、化合物
含氧酸、无氧酸
下列物质中属于纯净物的是
纯净的空气
纯净的氮气
盐酸
碘酒
下列物质属于纯净物的是
纯净的食盐水
冰水混合物
河水
清新的空气
下列物质属于纯净物的是
天然气
爆鸣气
冰水混合物
纯净的无污染的空气
下列几种物质水氧气氢气铁氯化钠海水属于混合物的是属于纯净物的是上述纯净物中属于单质的是属于化合物的是
下列物质中属于纯净物的是
18K黄金
水银
矿泉水
纯净的盐酸
下列物质中属于纯净物的是
纯净的空气
烧碱
75%的医用酒精
矿泉水
下列物质属于纯净物的是
冰水混合物
纯净的无污染的空气
天然气
碘酒
纯净物是由一种物质组成的下列物质属于纯净物的是
纯净水
纯净的空气
二氧化碳
矿石
下列物质属于纯净物的是
纯净的盐酸
冰水混合物
铝合金
净化后的空气
知道纯净物的含义是学好化学的前提下列物质一定属于纯净物的是
由同种分子构成的物质
由不同种分子构成的物质
由相同元素组成的物质
由不同种元素组成的物质
下列物质中属于纯净物的是
下列物质中前者属于纯净物后者属于混合物的是【】
医用酒精、空气
纯净水、冰水混合物
苛性钠、盐酸
黄铜、石灰石
研究物质的性质必须取用纯净物下列物质中属于纯净物的是
空气
啤酒
干冰
硬水
下列物质属于纯净物的是
米醋
洁净的空气
冰水混合物
纯净的自来水
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下列有关“配置50g溶质质量分数为6%的氯化钠溶液”的操作的是
某化学实验小组在完成“粗盐中难溶性的杂质去除”后从课本得知所得的盐中还含有可溶性杂质氯化镁氯化钙等为探究进一少除去氯化镁氯化钙方法它们做了如下的工作请你一道完成． 【查阅资料】A．氯化镁溶液可跟氢氧化钠溶液反应生成难溶的氢氧化镁和氯化钠． B．氯化钙溶液可跟碳酸钠溶液反应生成难溶的碳酸钙和氯化钠． 【实验设计】 【讨论交流】实验小组的同学对上述实验方案进行讨论认为通过以上操作还未得到纯净的氯化钠步骤“4”所得的固体可能还混有氢氧化钠和为得到纯净的氯化钠应在步骤“3”所得的滤液中加入适量的盐酸再蒸发．加盐酸可能发生的反应是写化学方程式． 【实验反思】分离提纯物质时所加的试剂只能与杂质反应过量的试剂要除去’不能使其成为新的杂质．
下列成语中主要包含化学变化的是
如图是某元素在元素周期表中的部分信息及原子结构示意图下列从图中获得的信息不正确的是
Theworld'sinsectsaregoingdownthepathofextinctionthreateningacatastrophiccollapseofnature'secosystemsaccordingtothefirstglobalscientificreview.Morethan40%ofinsectspeciesaredecliningandthirdareendangeredtheanalysisfound.Therateofextinctioniseighttimesfasterthanthatofmammalsbirdsandreptiles. Itshouldbeofhugeconcerntoallofusforinsectsareattheheartofeveryfoodweb.Theypollinate授粉thelargemajorityofplantspecieskeepthesoilhealthyrecyclenutrientscontrolpestsandmuchmore.Lovethemor1oathethemwehumanscannotsurvivewithoutinsectssaidProfDaveGoulsonattheUniversityofSussexintheUK. TheanalysispublishedinthejournalBiologicalConservationsaysintensive集约型agricultureisthemaindriverofthedeclinesparticularlytheheavyuseofpesticides.Urbanisationandclimatechangearealsosignificantfactors. Ifinsectspecieslossescannotbestoppedthiswillhavecatastrophicconsequencesforboththeplanet'secosystemsandforthesurvivalofmankind.Itisveryrapid.In10yearsyouwillhaveaquarterlessin50yearsonlyhalfleftandin100yearsyouwillhavenonesaidreviewauthorFranciscoSánchez﹣BayoattheUniversityofSydneyAustralia. Oneofthebiggestimpactsofinsectlossisonmanybirdsreptilesamphibiansandfishthateatinsects.Ifthisfoodsourceistakenawayalltheseanimalsstarvetodeathhesaid.SucheffectshavealreadybeenseeninPuertoRicowherearecentstudyrevealeda98%fallingroundinsectsover35years. MattShardlowattheconservationcharityBuglifesaidItisthoughtfultoseethisevidencethatshowsthepitifulstateoftheworld'sinsectpopulations.Itisincreasinglyobviousthattheplanet'secologyisbreakingandthereisaneedforastrongandglobalefforttopreventandchangetheseterribletrends. 1Whyarepeopleworriedabouttheinsectdecline? A.Theyarevitaltoecosystems. B.Theyprovidefoodforpests. C.Theypollinateallplants. D.Theyenrichthesoil. 2Whatisthemaincauseofinsectlosses? A.Moreandmoretrees. B.Restrictionsonpesticides. C.Upgradingagriculture. D.Friendlyenvironment. 3Wherecanyoufindtheexacttimeofinsectlosses? A.Inparagraph1. B.Inparagraph2. C.Inparagraph3. D.Inparagraph4. 4Whatcanbeasuitabletitleforthetext? A.Humanscansurvivethepunishmentofnature B.Insectdecliningisbreakingnature'secosystems C.Nature'secosystemsareinfluencedbyhumans D.InsectsandanimalsaredyingoutinPuertoRico
TheWorld'sLargestLibraries BritishLibraryUnitedKingdomLondon TheBritishLibrarywascreatedbyActofParliamentin1972previouslythelibraryhadbeenpartoftheBritishMuseumwherethefamouscircularreadingroomhadaccommodatedresearchersincludingKarlMarxwhoworkedon‘DasKapital'thereaswellasOscarWideandMahatmaGandhi.TheBritishLibraryisnowhousedinanewbuildinginSt.PancrasLondonwhereitstreasuresincludetwoGutenbergbiblestheLindisfarneGospelsandoneofLeonardodaVmci'snotebooks. LibraryofCongressUnitedStatesWashingtonD.C. Foundedin1800withtheprivatecollectionofThomasJeffersontheLibraryofCongressisineffecttheUSA'sNationalLibrary.ItreceivestwocopiesofeverythingpublishedintheUnitedStates.TheLibraryofCongresswagburnedbytheBritishArmyin1812andseverelydamagedbyfireagainin1851.ThecollectionincludesmanyrarebooksdrawingsandtwoStradivariusviolins. NewYorkPublicLibrary TheNewYorkPublicLibrarydevelopedgraduallyinthenineteenthcenturyfromthemergerandacquisition收购兼并ofanumberofpublicandprivatecollectionsithasmanybranchesindifferentdistrictsofNewYorkCity.Itremainsastructurewhichcombinespublicandprivatefinanceandgovernance.TreasuresheldatthelibraryincludeaGutenbergBible. RussianStateLibraryMoscow Foundedin1862astheMoscowpubliclibraryandmuseumthiscollectionbecametheStateLibraryin1925.InconsequenceitreceivescopiesofallRussianpublicationsandalsoholdslargecollectionsofmapsjournalsmusicscoresandrecordings.ItspossessionsincludetheArchangelGospelacodexintheSlavoniclanguagedatingfrom1092. 1Whichlibrarymetwithtwobiglossesinhistory? A.BritishLibrary. B.LibraryofCongress. C.NewYorkPublicLibrary. D.RussianStateLibrary. 2WhatcanwefindintheRussianStateLibrary? A.LindisfameGospels. B.Stradivariusviolins. C.AGutenbergBible. D.TheArchangelGospel. 3Whatdoweknowfromthetext? A.KarlMarxandOscarWideworkedaslibrariansintheBritishLibrary. B.TheLibraryofCongressreceivestwocopiesofallpublicationsinRussia. C.TheNewYorkPublicLibraryissupportedbystateandpersonaldonation. D.TheRussianStateLibrarypossessesaGutenbergBibleinSlavonic.
金属钻Co与铁具有相似的化学性质． 1钴可形成化合价为+2和+3的两种氧化物其化学式分别是． 2已知CoCl2固体是蓝色的CoCl2溶液是粉红色的．将金属钴投入稀盐酸中发生置换反应生成+2价钴的盐溶液和氢气反应的化学方程式是可观察到的现象是．
物质的用途与利用的性质对应关系正确的是
请从①一氧化碳②熟石灰③甲烷④二氧化碳⑤小苏打⑥水这六种物质中按选择适当的物质填空填数字序号． 1最常用的溶剂是． 2有毒的气体是． 3可改良酸性土壤的碱是． 4可制汽水的气体是． 5可做面点发酵剂的盐是． 6可燃冰的主要成分是．
After20yearsofmarriagemywifewantedmetotakeanotherwomanoutto1.ShesaidIloveyoubutIknowthisotherwomanlovesyoutoo. Theotherwomanthatmywifewantedmetovisitwasmymotherwhohasbeenawidow寡妇for19yearsbutmybusylifehadmadeitimpossibletovisither2.ThatnightIcalledto3heroutfordinner. What'swrong?areyouwell?sheasked.Mymotheristhetypeofwomanwhosuspectsthatalatenight4isasignofbadnews. IthoughtthatitwouldbepleasanttospendsometimewithyouI5. Shethoughtaboutitforamomentand6.Duringthedinnerwehadanagreeableconversation﹣7extraordinarybutrecenteventsofeachother'slife. Beforewe8shesaidI'llgooutwithyouagain9onlyifyouletmeinviteyou. Afewdays10mymotherdiedofaheartattack.It11sosuddenlythatIdidn'thaveachancetodoanythingforher.AfewdaysafterthefuneralIreceivedanenvelopewithareceipt收据fromthesameplacewheremotherandIhad12.Anattachednote13 Ipaidthisbill14.Iwasn'tsurethatIcouldbetherebutneverthelessIpaidfortwo15﹣oneforyouandtheotherforyour16.Youwillneverknowwhatthatnightmeantforme.I17youson. AtthatmomentI18theimportanceofsayingintimeILOVEYOU.Giveyourfamilythe19theydeservebecausesometimesthingscannotbe20tillsomeothertime. 1A.home B.talk C.movie D.dinner 2A.directly B.frequently C.rarely D.exactly 3A.bring B.take C.force D.invite 4A.visit B.meal C.ring D.date 5A.argued B.whispered C.committed D.responded 6A.agreed B.refused C.promised D.nodded 7A.anything B.nothing C.something D.everything 8A.met B.parted C.left D.divided 9A.but B.and C.so D.or 10A.before B.earlier C.ago D.later 11A.broke B.formed C.fell D.struck 12A.sat B.waited C.gathered D.dined 13A.saw B.read C.showed D.wrote 14A.inadvance B.onpurpose C.byaccident D.withpatience 15A.tables B.dishes C.seats D.chances 16A.mother B.family C.wife D.child 17A.miss B.admire C.love D.hug 18A.sensed B.accepted C.checked D.pursued 19A.time B.money C.comfort D.calls 20A.ensured B.delayed C.forgotten D.forgiven
化学与生活密切相关． 1下表是中学生每人每天摄入部分营养素的参考值 人体活动所需能量主要由糖蛋白质和提供人体贫血是因为缺下列食物中含蛋白质较丰富的是填序号 a．鸡肉炖豆腐b．清炒小白菜c．红烧土豆丁 2如图是某品牌服装标签的部分内容 请根据标签提供的信息冋答在面料中属于有机合成纤维的是区分羊毛与合成纤维的简单实验方法是． 3汽车是目前人类的主要交通工具．生产汽车消耗最多的金属材料是燃油汽车排放的尾气中有CO2COH2O会污染空气的是．城市里用电动汽车代替燃油汽车可以有效改善城市空气质量电动汽车中的锂电池含有磷酸铁锂LiFePO4在磷酸铁锂LiFePO4中若锂和铁的化合价分别为+1+2则磷的化合价为．
Vehiclesoftencomeintoconflictwithothervehiclesandpedestrianswhentheirintendedcoursesoftravelintersect交叉andendupbeingineachothersway.Thegeneralprinciplethatestablisheswhohastherighttogofirstiscalledrightofwayorpriority.Itdetermineswhohastherighttousetheconflictingpartoftheroadandwhohastowait.Signssignalsmarkingsandotherfeaturesareoftenusedtomakepriorityclear. Adrivermustyield让therightofwaytootherdrivers ●WhenapproachingaYIELDsign.Slowdownorstoptoavoidacrash. ●Evenafterthelightturnsgreenwhentherearevehiclesintheintersection. ●Whenapproachingemergencyvehiclesusingsoundingorflashingsirens. ●Aftercomingtoacompletestopatanintersectionwherethereisastopsignoraflashingredsignal.Ifthereisnostoplinestopbeforethecrosswalk. ●Whenmakingaleftturnonaredlightafterastopfromaone﹣waystreettoanotherone﹣waystreetwithtrafficmovingtotheleft.SeeFigureA. ●Whentwovehiclesondifferentroadwaysarriveatafour﹣waystopintersectionatthesametimethevehicleshouldyieldtothevehicleonitsright.SeeFigureB. ●Whencomingoutofanalleybuildingprivateroadordrivewayaftercomingtoacompletestop.SeeFigureC. ●WhencrossingtrafficattheendofaTroadwithnotrafficcontrolsignsorsignals.SeeFigure D. 1What'sthepurposeofthetext? A.Toexplainthelawofrightofway. B.Toillustratetrafficsignsandsignals. C.Toinformdriversofgeneraltrafficrules. D.Tointroducetrafficrulestopedestrians. 2Whichistherightbehavioraccordingtothetext? A.Driveononcethelightturnsgreen. B.Keepdrivingifthereisnostopline. C.Yieldtoemergencyvehiclesatanytime. D.SlowdownwhenapproachingaYIELDsign. 3WhichofthefollowingdescriptionisTRUEaccordingtothefigures? A.FigureABshouldyieldtoA. B.FigureBAshouldyieldtoB. C.FigureCAshouldyieldtoB. D.FigureDAshouldyieldtoB.
水是人类生活不可缺少的物质下列有关水的叙述错误的是
IntheU.S.stateofWashingtonaroadcalledInterstate90cutsthroughawildmountainousareatoreachthecityofSeattle.Forthearea'smanykindsofanimalsthebusyhighwaygreatlylimitstheirmovements.Animalsneedtomovetofindfoodtofindmatesandtofindnewplacestolive.CrossingI﹣90astheroadiscalledisariskybutsometimesnecessaryact.Butsoonanimalswillhaveasaferchoice. Tohelptheanimalsthestateisfinishingworkonitslargest﹣everwildlifebridge.The11﹣meter﹣tall20﹣meter﹣widebridgebeginsintheforest.Workersareaddingfencinganti﹣plantstohelpguidetheanimalsacrossthebridge.TheI﹣90bridgeispartofagrowingnumberofwildlifecrossingsacrosstheUnitedStates.Somearefencessomeareoverlandbridgesandsomeareunderpasses.Theyallaimtokeepdriversandanimalsawayfromeachother. AU.S.TransportationDepartmentstudyfoundcrashesbetweenanimalsandhumansroseyearbyyear.Theaccidentsmadeupabout5percentofallcrashesnationallyandcosttheeconomyabout﹩8billion.Suchcostscomefromcarrepaidemergencyroomvisitsandremovalofthedeadanimalsonroads.Collisionsbetweenanimalsanddriversarerarelydeadlytopeople.Buttheyareoftendeadlytowildlife.Thestudyalsofoundthat21endangeredorthreatenedspeciesintheU.S.areaffectedbyvehiclehits. PattyGarveyDardaoftheU.S.ForestServicesaysthe﹩6﹣millionbridgewillonedaypayforitselfbecausethehighwaywillnothavetobefullyorpartlyclosedeachtimealargeanimalisstruck.IfyoushutdownInterstate90youshutdowninterstatetrade.sheadds. 1Whyismovingacrosshighwaysnecessaryforanimals? A.Tosurvive. B.Tofindfood. C.Tofollowtheirhabit. D.Tofreetheirmovements. 2WhatarethosewildlifecrossingsintheU.S.builtfor? A.Avoidinghumandeaths. B.Preventingcaraccidents. C.Increasinginterstatetrade. D.Protectingwildanimals. 3WhatdoestheauthorintendtodoinParagraph3? A.Highlighttheharmcausedbycaraccidents. B.Showthecostsrelatedtocar﹣animalcrashes. C.Explainthenecessityofwildlifecrossings. D.Presenttheurgencytoprotectwildspecies. 4WhatisDarda'sattitudetowardsthebuildingofI﹣90? A.Opposed. B.Concerned. C.Favorable. D.Indifferent.
A～F是教案备课库常见的六种物质它们之间的关系如图所示“→”表示物质间的转化关系“﹣”表示两种物质能相互反应部分反应物生成物及反应条件未标出．物质A可以与酸碱盐三类物质发生反应D是厨房中常用的调味品F的溶液呈黄色反应①和②都有白色沉淀生成请回答 1写出ACD的化学式ACD． 2写出①的基本反应类型是． 3反应②的化学方程式为．
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气体的溶解度也有一定的变化规律． I打开可乐瓶逸出大量气泡．由此可见压强越小CO2的溶解度越．为增大CO2的溶解可采用的一种方法是． II不同温度下氧气的溶解度随压强的变化如图所示图中t1℃对应的温度为40℃则t2对应的温度填编号． a．大于40℃b．小于40℃c．无法确定．
A﹣﹣H是初中常见的物质其中B能作干燥剂E为黑色粉末H为蓝色难溶固体．它们之阆的反应关系如图部分物质和反应条件已略去回答下列问题 1E为． 2写出下列化学方程式①②③．
AtthebeginningofChineseYearofthePigavideocalledWhatisPeppaPigmadeapinkpigthe1hotimageinChina.Thevideofeaturesanelderlymanlivinginthecountryside.2giveaNewYeargifttohisgrandsoninthecityhewonderswhatPeppaPigis.Theelderlymain3eventualmakesaPeppaPigbyhimselfbasedonablowingmachine.Thevideo4conveysthemessageoffamilyreunionandagrandfather'slovewon1500millionclickswithin24hours.Andthepopularcartooncharacterwithitsroundbellyandbigearshaslongbeentaken5asymbolforabundancewealthandgoodluckinChineseculture.Thepeppaalongsideherfamily6becomeaglobalhitsincethecartoon'sreleasein2004.Thechildren'sTVshowissopopularbecauseitisoneofthefewthatfamiliescanenjoytogetherwithoutadultsfeeling7bore.The8producemadehisfortunethankstotheyoungpeppapig.9itcomestothesecretofsuccessheexplainedthathetriedto10simpletheshowandensuredthepigletisunforgettable.
甲乙丙丁4种物质在密闭容器中充分反应．测得反应前后各物质的质量如表．下列说法正确的是
Adayinthelifeofasunbeariswhatyoumightexpectfromthenamesunny.Initsnaturalhabitatthesunbearspendsover80percentofitsactivewakingtimeindaylight. Butwhendisturbedbyhumanactivitythatchangesdramatically.Inareaswherepeoplearepushingintothesunbear'shabitattheanimalsarespending90percentoftheirwakingtimeafterdark.Effectivelythethreatofhumanpresenceismakingthesunbearchangeintothemoonbear. LedbyscientistsattheUniversityofCaliforniaBerkeleythestudyfoundthathumanactivityisdrivingscoresofmammalstoshifttheiractivityfromthedaytimeintothedarkhoursofthenight.Asmanyanimalshavealreadybeenforcedoutoftheirlocalhabitatsothersareattemptingtoavoidinteractionwithhumansbyseparatingthemselvesintimeratherthaninspace. Fortheworktheresearchersexaminedthebehaviorsof64mammalspeciesincludingdeertigersboarsandofcoursesunbears.Theyobservedincreasednocturnal夜间的behaviorinalargemajorityofthemwithspeciesthatarenaturallyactiveduringthedaytendingtoshifttheiractivitytoafterdarkandthosethatarenaturallynocturnalbecomingmoreso.Themammalsaffectedrangedacrossbodysizehabitattyperegionoftheworldanddiet. Humanactivityofallsortsaffectanimalslivesincludingactivitieslikehuntingagricultureandlanddevelopmentharvestinglocalnaturalresourcesevenhikingorwalkingthroughwildareas.SporthuntingintheHwangeNationalParkinZimbabwedroveantelopestospendmoreoftheiractivewakinghoursatnightrestrictingtheiraccesstowater.SimilarlyhikersintheSantaCruzMountainsinCaliforniamadecoyotes郊狼morenocturnalforcingthemtofindnewpreys猎物amongtraditionallynocturnalanimals. Theresearcherswarnthatprofoundshiftsinthenaturalbehaviorpatternsofsomanyspeciesdisturbdynamicsthathaveevolvedovergenerationsleadingtoaseriesofunknowneffectsontheentireecosystems. 1Whatdidthestudyfind? A.Moreanimalsseparatethemselvesinspace. B.Humanactivitychangesanimals'wayoflife. C.Manyanimalswerepushedoutoftheirlocalhabitats. D.Thesunbearspendsover80%wakingtimeindaylight. 2Whatdoestheunderlinedwordthatreferto? A.Thesunbear. B.Thewakingtime. C.Humanactivity. D.Thenaturalhabitat. 3Whatcanweinferfromparagraph5? A.Antelopeshaveeasieraccesstowater. B.Coyoteshavetopreyonnewtypesforsurvival. C.Humanactivityshortensanimals'sleepingtime. D.Animalshavemanagedtoescapeinteractionwithhumans. 4Whatdoestheauthorwanttotellusinthetext? A.Humanthreatmakesthesunbearnocturnal. B.Animalsarebadlyhurtbyhumanpresence. C.Animalsbecomemoreadaptablethankstohuman. D.Ecosystemsmaybereshapedduetohumanactivity.
水品的主要成分是二氧化硅SiO2下列关于二氧化硅的说法错误的是
Currentdigitaltechnologygivesusmusicofflawlessquality.Italsomakesiteasiertocopyuploadandstreammusicwithouthavingtodownloadit.1.Howeverasclimatechangeisoneveryone'smindthesedaysthequestionrelatedtomusicarisesWhichmusicconsumptionformisworsefortheenvironmentCDsvinyl黑色胶片ordigitalmusic?Theanswermightsurpriseyou. 2logicwouldsuggestthatmusicdownloadsandonlinestreamingaregoodfortheenvironment.Butmustitsurelybemoreenvironmentallyfriendly?Eventhoughstreamedmusicismaterial﹣freethatdoesn'tmeanitdoesn'thaveanenvironmentalimpact.Infacttheinformationissearchedandsenttoourelectronicdevicesacrossthenetworkwhichcostsenergy.3. ResearchersfoundthatstreaminganalbumovertheInternetwilluse27timesmoreenergythanittakestoproduceasingleCDorvinylrecord.Inanygivensecondthemusicplatformisservingabout2.5millionstreamsatthesametime.4thatmeansalmost210000albums'worthofmusichasbeenstreamed.Itwillusenearly8000timesmoreenergythanwhatmakingoneCDtakes.MeanwhileifyoubuyaCDit'stherepermanently.TheonlyextraenergyrequirediswhateveryouneedtopoweryourCDplayer. ThestudywaspublishedbeforeRecordStoreDay﹣﹣aneventthatencourageslistenerstobuyphysicalrecord.5.Rathertheywantyoutothinkaboutyourpoweruseandchooseservicesthatminimizetheireffectontheplanet.Theyalsohopethiscoulddevelopalternativesthataremoresustainablewithoutsacrificingtheconvenienceyouexpect. A.Sinceourdigitalmusicuseslessplastic B.Ifaveragealbumscontaintwelvetracks C.Thishappenseverytimewestreammusic D.Asaresultstreamingmusicbecomespopular E.Althoughstreamingmusicisagreeneralternative F.Itwantstoconveyeffectsofstreamingoneconomy G.Buttheresearchersaren'tadvisingplayingmusictraditionally
下列关于水的说法正确的是
如图是甲乙两物质的溶解度曲线下列说法正确的是
假定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写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词符号^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. Weloveourcampuscanteenlocatednextbyourdormitory.Alltheyeararounditprovideduswithhealthydeliciousanddiversefood.Everydaywecanenjoyourmealsinthecleanerandtidydininghallwithpleasantlightbackgroundmusic.Afriendlyandpatientstaffinthecanteentreatmeastheirownchildren.Theyneverfailtomakeushappyandrelaxedwiththeirsmilefacesandwhatcan'tbeignoredisthathowthepriceofthemealisquitereasonable.InviewofallthisstudentslovinglycallHappinessCanteen.IamsurelyIwillmissitevenaftermygraduation.
“双吸剂”是常用的食品保鲜剂可用来吸收氧气二氧化碳水蒸气等气体．某化学小组的同学在袋装食品中发现一包久置的双吸剂．其标签如图所示． 【提出问题】久置固体的成分是什么 【收集资料】 1查阅资料铁与氯化铁溶液在常温下生成氯化亚铁Fe+2FeCl3＝3FeCl2． 2打开固体包装观察部分粉末呈黑色部分粉末呈白色另有少量红棕色的块状固体． 【作出猜想】久置固体中可能含有FeFe2O3CaOCaOH2CaCO3．猜想固体中可能含有Fe2O3的依据 是． 【实验探究】下表是甲组同学设计并记录的实验报告请你补充完整． 【实验质疑】乙组同学认为甲组同学第二步操作得出的结论不合理理由是用化学方程式表示．甲组同学第三步操作得出“一定不含有Fe2O3“的结论也是错误的理由是． 【继续探究】为验证固体中是否含有Fe2O3乙组同学用磁铁先分离出铁粉向残留固体中加入足量稀盐酸若溶液呈色证明固体中含有Fe2O3写出该反应的化学方程式．
下列实验操作现象和结论一致的是
用元素符号或化学式填空 1三个碳原子2五个二氧化氮分子 3铁离子4天然气主要成分
假定你是李华你校举办了一场用英语讲好中国故事的主题演讲活动请你写一则英文报道.要点如下 1.时间和地点 2.活动的过程 3.活动的意义. 注意1.词数100左右2.可以适当增加细节以使行文连贯.
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