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有关实验操作正确的是（ ）
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正确的操作才能保证实验的顺利进行.请填写下列有关实验操作中的空格1用酒精灯给物质加热时要用酒精灯火焰
下面有关误差说法中正确的是
实验中产生的错误叫误差
误差是实验时不遵守操作规则而引起的
认真测量可以避免误差
多次测量求平均值的办法，可以减小误差
某课题研究小组为探究生长素类似物—萘乙酸NAA是否与植物开花有关进行了如下实验方法取大小不等的水仙球
正确的实验操作是完成实验任务的保证下列有关实验操作的说法中不正确的是
称量氢氧化钠固体时，应将其放在烧杯中称量
使用药匙取用粉末状药品
酒精洒在实验桌上燃烧起来，立即用湿抹布盖灭
加热试管内的液体时，将试管口朝向有人的方向
下列有关实验操作现象和解释或结论都正确的是
A
B
C
D
正确的实验操作是化学实验顺利进行的保证.请填写下列有关实验操作中的空格1点燃可燃性气体时都要先再点燃
有关实验记录正确的为
实验记录中实验操作者的名字可以用缩写或特定符号表示
实验记录存档后就不能调出查阅
实验如果失败，则不必填写实验记录
实验记录应该记下实验过程中发生的操作及仪器等的特殊情况
为节省操作时间，实验记录可在实验结束后补记
下列有关实验操作或现象的叙述正确的是
教师应学习研究有关实验室安全的知识同时在理论教学和实验中对学生进行安全知识教育教会学生如何正确使用实
正确的操作能保证实验顺利进行.请填写下列有关实验操作中的空格1做细铁丝在氧气中燃烧的实验时集气瓶底应
具备基本的化学实验技能是进行科学探究的基础和保证下列有关实验操作正确的是
给液体加热
转移溶液
称取NaOH固体
量取液体
正确的操作能保证实验顺利进行.请填写下列有关实验操作中的空格1做细铁丝在氧气中燃烧的实验时集气瓶底应
正确的操作能保证实验顺利进行.请填写下列有关实验操作中的空格1用酒精灯给物质加热时要用酒精灯火焰的2
正确的操作能保证实验顺利进行请填写下列有关实验操作中的空格1用酒精灯给物质加热时要用酒精灯火焰的__
有关实验操作正确的是
滴加液体
取用固体
测溶液pH
过滤
正确的操作能保证实验顺利进行.请填写下列有关实验操作中的空格1用酒精灯给物质加热时要用酒精灯火焰的2
在需要带电操作的低电压电路实验时下列哪种是正确的
双手操作比单手操作安全
单手操作比双手操作安全
单手操作和双手操作一样安全
操作与空气湿度有关
下列有关实验的操作正确的是
A
B
C
D
正确的操作能保证实验的顺利进行.请填写下列有关实验操作中的空格1用酒精灯给试管里药品加热时要先再对准
下列有关实验原理或实验操作正确的是
用广泛pH试纸测得饱和氯水的pH约为2
用量筒量取7.60 mL0.l mol/L盐酸
用图1所示的操作可检查装置的气密性
实验室用图2所示的装置制取少量的NO
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用数字12346组成没有重复数字的五位数其中偶数的个数为
三氯生X是一种广谱抗菌化合物．广泛添加于肥皂洗手液牙膏洗洁精化妆品沐浴露等个人护理用品中．三氯生的合成路线如图 1E的系统命名为．反应②的反应类型为．F分子中含饭官能团的名称是． 2已知D中不含有氯元素则D的结构简式为． 3反应①的化学方程式为． 4下列有关三氯生X的说法正确的是． A．分子中有7个原子位于同一直线上B．可与水以任意比互溶 C．能与FeCl3溶液发生显色反应D．苯环上的一溴代物有2种 5写出一种满足以下条件的三氯生X的同分异构体的结构简式． ①分子结构中只有1个苯环．且苯环上有4个侧链 ②有3种类型的官能团．其中一种为酚羟基 ③核磁共振氢谱有3组峰．峰面积之比为322 6根据题设信息．设计以甲苯为原料合成的线路其他试剂任选．
Itstartedwithawomanwhowasn'tdoinganythingparticularlyawfulbutIjustfeltunhappywhenIlookedatthephoto.Icouldn'teventellyouwhatexactlythepicturewasbutIjustrememberthefeelingthatcameoverme:annoyanceandunhappiness. IthappenedagainafewweekslaterwithaphotoofacollegestudentthatIrememberasnotbeingverynice.SuddenlyIdecidedthatI'dhadenough.Idon'tneedtofollowthesepeopleonsocialmedia.WhyamIfloodingmylifewithpeoplethatmakemeunhappy?Iunfollowedher.AndthenIbegantoridmysocialmediaplatformsofpeoplewhodidn'tmakemehappy. Workingasasocialmediastrategist1finditalmostimpossibletogiveupallsocialmediaplatformsbutitalsodidn'tneedtomakemeunhappywheneverIwasonitthroughouttheday.BesidesIlikesocialmediawhenit'sahealthyspaceforme.SoinsteadoftheextremechoiceofgivingitallupIdecidedI'dfillmyfeedwiththepeopleandthingsthatimprovedmymood. Beingselectiveaboutthepeopleyousurroundyourselfwithisimportantforyourhealthandself﹣care.WhenIrealizedhowmuchbetterIfeltwhenIdidn'tseethatbloggerpostvideothatmademerollmyeyesorapicturethatbroughtmetotearsIknewIhadmadetherightdecision. NowmyfeedfillsmewithjoywhenIseemyfriendspostabouttheirphotosandblogsfromwhichIdrawinspiration.Socialmediadoesn'thavetobetheterribleplaceeveryonesaysitisbutyouhavetobewillingtomakethefirstmovetomakeitthatway. 1Howdidtheauthorfeelwhenseeingaphotoofcollegestudent? A.Embarrassed B.Confused C.Upset D.Concerned 2Howdidtheauthordealwithpeopleonsocialmedia? A.Shedidherbesttomakefriendswiththem B.Shewipedoutthosewhomadeherunhappy. C.ShewarnedthemofthedangeronSocialmedia D.Shefeltsorryfornotstayingintouchwiththem. 3Whatmightbeadvisedtodoonsocialmediaaccordingtoothetext? A.Followpeoplewhoposthappythings. B.Learntoenjoyyourfriends'posts. C.Makecommentsafteryourfriendsposts. D.Sharehappinessandsorrowwithyourfriends. 4What'sthemainideaofthetext? A.Changingmyattitudebenefitsmegreatly. B.It'stimetolimitourtimespentonsocialmedia. C.Peoplealwaysmakesmeunhappyonsocialmedia. D.Deletingpeoplefromsocialmediachangesmyfeeling.
i是虚数单位＝
水系钠离子电池安全性能好价格低廉对环境友好有着巨大的市场前景．右图为某钠离子二次电池工作原理示意图电池反应为2NaFePO4F+Na3Ti2PO432Na2FePO4F+NaTi2PO43．下列说法错误的是
Bytheendoftheyeara3D﹣printedbridgewillbeputtouseinChinaforthefirsttime. Different1traditionalbridgesits2createdesigndoesn'tusereinforcedconcrete.Itismadeofanewmaterial3designtoweatherrainandsunfor4extendedperiodandthat'sdurableenoughtomeetnationalconstructionindustrystandards.Ifpartsofthebridgebecomedamagedtheycanberepaired5separate. The15﹣meter﹣longfootbridgeinShanghai6willhaveservicelifeofupto30yearswilltake35daystobuildaccordingto7itchiefarchitect.Thecomplexcurvedsurfacesofthebridgecanonlybeachievedby8use3Dprintingtechnology.Basedonlaboratorytestingitcanbearaloadof250kilogramspersquaremeter. Thisisn'tthefirsttimethata3D﹣printedbridge9makeinChina.InJulylastyearTongjiUniversityinShanghaimadetheworld'sfirsttwo3D﹣printedpedestrianbridges. 10thatpairofbridgeswasonlybuiltasademonstrationandnotforactualuse.
如图已知多面体PABCDE的底面ABCD是边长为2的菱形PA⊥底面ABCDED∥PA且PA＝2ED＝2． 1证明平面PAC⊥平面PCE 2若直线PC与平面ABCD所成的角为45°求二面角P﹣CE﹣D的余弦值．
Thewordtoleranceiswidelyusedinliberaldemocracies自由民主.Itindicatesapositivemeaning.Politiciansurgeustobetoleranttowardsminorities.Educatorsteachustobetoleranttowardstheother.Thepressisfullofreferencestotheneedtodisplaytolerancewhenfacedwithindividualsorgroupsespousingadifferentvieworholdingadifferentreligiousbelief.Atolerantsocietyisanobjectivesoughtafterbyanyonewhobelievesinthevaluesofdemocracy.Atolerantindividualisconnectedwithvirtuousqualities. Thequestionwemustaskiswhetherwehavebeenusingthewordtolerancefullyawareofitsmeaningandwhetherwehaveapplieditcorrectlytoreflectwhatwereallywishtoconvey. Thewordtolerancemeanstobearortobearwith.IfItoleratesomethingorsomeoneIbasicallysaythatIamreadytobearitorhim.Icantolerateabadsmelloranoisyneighbour.TheactoftolerationforcesmetodesistfromconveyingmyobjectiontotheexistenceofaphenomenonwhichIfinddifficulttobear.Abadsmelloranoisyneighbourisconsideredbymetobeanobjectionablephenomenon.BytoleratingeitherofthemIamnottransformingthebadsmellorthenoisyneighbourintopositivephenomena.Let'sbehonest:Idon'thaveadifferenttastewhenitcomestobadsmells.Isimplydislikeitandhopethatitdisappears.Idon'trespectthenoisyneighbour.IwouldratherhavehimstopatoncethenoiseheismakingsoIcanliveinpeace. Thesubjecttoleratingisbynaturenotequaltotheobjectbeingtolerated.IfItolerateyouIessentiallysaythatIamaboveyouandampreparedalthoughunwillinglytobearwithyourpresenceorwithyourpracticesoropinions.Thatmaybetrueinthecaseofanindividualwhoisreadytotoleratetheother.Howeverthisattitudebysuchanindividualthoughempiricallytrueishardlyavirtue.Certainlythefactthatanindividualinrealitymaymerelytoleratetheotherorhisopiniondoesnotjustifyagovernmentoranyofficialauthoritypromotingtoleranceasavirtue.Onecannottolerateanequalbeing.Trueequalityinvolvesrespectnottoleration.Torespecttheotherasadistinctivepersonishardlytotoleratehim.Thisisthetruemeaningofequality:diversityexistinginamutually﹣respectfulsocio﹣legalsetting. Atolerantattitudeinvolvesthegrantofafavournotaright.Thequestionweshouldaskourselvesiswhetherwewouldeverwishaparliamenttomakelawsconsideringusasindividualsandaspartofacollectiveentityorapermissiontopursuecertainactionsinterpretedasafavourratherthanaright?Indeedwouldweeverwishanyonetolistentoourviewsandacceptusthewaywearesimplybecauseheiskindenoughtotolerateus? 1Thefirsttwoparagraphsaremainlyintendedtoshowthat. A.toleranceisasymbolofliberaldemocracies B.democraticsocietyalwaysadvocatestolerance C.people'sunderstandingoftoleranceisone﹣sided D.tolerancecanbeappliedtomanysituations 2Theexampleofabadsmellandanoisyneighbourisraisedtoindicatethat. A.thewriterarefedupwiththem B.mostpeoplefindthemhardtotolerate C.thewriterisn'tprejudicedagainstthem D.toleratingthemisn'tavirtuousact 3ThemainideaofParagraph4isthat. A.toleranceshowsanunequalrelationship B.mostpeoplepromotetoleranceasavirtue C.peopleshouldshowrespectforeachother D.tolerancehasnothingtodowithrespect 4Whichcanbethebesttitleforthispassage? A.ToleranceandRespect B.WhatIstoBeTolerated? C.IsToleranceaVirtue? D.ShouldPeopleBeTolerant?
InthewintermonthsthetemperatureinmostofCanadausuallystaysbelow0℃.HoweverinsomepartsofCanadasuchassouthernBritishColumbiathetemperaturerarelygoesbelow0℃.Inmostareaswherepeoplelivesnowwillbeonthegroundfrommid﹣Decembertomid﹣March.ThoughCanada'swintermaybemuchcolderandlongerthanyouareusedtoitcanbeveryenjoyable.FormanyCanadiansbeingactiveinwinterisanimportantpartofenjoyinglife.Therearemanyoutdoorwinteractivitiesincludingskiingicefishingwalkingandskating.Joininginoneoftheseactivitiesmayhelpyouappreciatewinterandenjoyyourtimeoutsideinthesnow. Dressingforwinter DuringwinterinCanadayouwillneedwarmclothing.Ifpossiblearrivewiththeseitemsorbepreparedtobuythemsoonafteryourarrival.Youwillneed: ☆warmwaterproofboots☆ascarfforyourneck ☆ahatthatcoversyourears☆glovesforyourhands ☆thickwintercoatspantsandsweaters Layerskeepyouwarm It'sagoodideatolayeryourclothingbyforexamplewearingaT﹣shirtandasweaterunderneathajacket.Ifyoubecometoohotit'salwayseasiertoremoveapieceofclothingthantoaddanother.OntheWestCoastpreparetodressforcoolrainyorsnowyweather.Youwillneed: ☆awarmwaterproofcoat☆waterproofhats ☆anumbrella☆rainbootsorsnowboots LearnmoreaboutweatherandseasonsacrossCanada.YoucanalsocontactRelatedLinksforexampleanimmigrant﹣servingorganizationinthecommunitywhereyouliveformoreinformationaboutdressingforwinter. 1Whatisthemainpurposeofthefirstparagraph? A.TotellaboutthedetailsaboutCanada. B.Toshowmanyoutdoorwinteractivities. C.TointroducethedailylifeofCanadians. D.ToencourageyoutoenjoywinterinCanada. 2IfyouspendawinterinCanadayou'llpreparethefollowingEXCEPT. A.anumbrellaandsunglasses B.thickwintercoatsandpants C.waterproofhatsandcoats D.snowbootsandgloves 3Inwhichpartofanewspapercanyoufindthispassage? A.Business. B.Sports. C.Tourism. D.Health.
若点P为抛物线Cy＝2x2上的动点F为C的焦点则|PF|的最小值为
WhenIwasafreshmanincollegeIreceivedaletterthatforeveropenedawindowinmysoul.Ihadjuststartedwritingandthe1ofmylocalcountynewspaperhadbeenkindenoughto2someofmywork.Aboutamonthlaterthe3arrived. Hereiswhatitsaid.Youmaynot4me.Welastsaweachotherinkindergartenandmy5movedthenextyear.We6getthecountypaperinthemailthoughandwhenIsawyournameIhadtowriteyou.Youseethatfirstyearinschoolwasvery7forme.Iwasatiny8andordinary﹣lookinggirlthattheotherchildren9meeveryday.ThethingIrememberaboutyouisthatyou10did.Whenwe11togoouttheteacheralwaysputmebesideyouandyouwouldholdmyhandaswe12thestreet.Youtalkedtomeandplayedwithme.You13measapersonnotsomeonedifferentandIwillbeforever14forthat.Mywholelifewas15becauseofhowyoutreatedmeallthoseyearsago. Icarefullywrotebacktomykindergartenfriendandwe16forseveralyears17theillnessthatshehad18withsincechildhoodfinallytookherlife.IwillneverforgethoweverjusthowmuchthatsimplekindnessIhadshared19toher. Everyactofkindnesswedo20another'sheart.Everybitofgoodnesswesharemakestheworldabetterplace.Let'susethatpowerandmakebothEarthandHeavensmile. 1A.teacher B.director C.editor D.leader 2A.print B.publish C.report D.check 3A.newspaper B.message C.work D.letter 4A.remember B.recognize C.hear D.forget 5A.parents B.family C.school D.classmates 6A.still B.also C.just D.even 7A.busy B.happy C.difficult D.easy 8A.honest B.naughty C.sunny D.sick 9A.kidded B.helped C.hated D.beat 10A.occasionally B.never C.seldom D.always 11A.gotup B.linedup C.endedup D.cheeredup 12A.adventured B.visited C.cleaned D.crossed 13A.judged B.heard C.knew D.saw 14A.grateful B.hopeful C.regretful D.skillful 15A.harder B.better C.easier D.healthier 16A.cooperated B.corresponded C.lived D.worked 17A.after B.when C.before D.while 18A.experienced B.studied C.treated D.struggled 19A.meant B.done C.appeared D.got 20A.discovers B.obtains C.enriches D.touches
甲乙丙三位同学被问到是否看过ABC三本书时甲说我看过的比乙多但没看过C书乙说我没看过B书丙说我们三人看过同一本书．由此可判断乙看过的书为
全球碳计划组织GCPTheGlobalCarbonProject报告称2018年全球碳排故盆约371亿吨．达到历史新高． 1中科院设计了一种新型的多功能复合催化荆实现了CO2直接加氢制取高辛烷值汽油其过程如图甲所示． ①已知CO2g+H2g═COg+H2Og△H＝+41kJ•mol﹣1 2CO2g+6H2g═CH2＝CH2g+4H2Og△H＝﹣128kJ•mol﹣1 则上述过程中CO转化为CH2＝CH2的热化学方程式是． ②下列有关CO2转化为汽油的说法正确的是． A．该过程中CO2转化为汽油的转化率高达78% B．在Na﹣Fe3O4上发生的反应为CO2+H2＝CO+H2O C．中间产物Fe5C2的生成是实现CO2转化为汽油的关键 D．催化剂HZSM﹣5可以提高汽油中芳香烃的平衡产率 ③若在一容器中充入一定量的CO2和H2加入催化剂恰好完全反应且产物只生成C5以上的烷烃类物质和水．则起始时CO2和H2的物质的量之比不低于． 2研究表明．CO2和H2在一定条件下可以合成甲醇．反应方程式为 Ⅰ．CO2g+3H2g⇌CH3OHg+H2Og．一定条件下往2L恒容密闭容器中充入1.0mo1CO2和3.0molH2在不同催化剂作用下合成甲醇相同时间内CO2的转化率随温度变化如图乙所示． ①催化效果最佳的是催化剂填“A”“B”或“C“b点时v正v逆填“＞”“＜”或“＝”． ②已知容器内的起始压强为100kPa．若图乙中c点已达平衡状态则该沮度下反应的平衡常数Kp＝保留两位有效数字Kp为以分压表示的平衡常数分压＝总压x物质的量分数． ③在莱催化剂作用下CO2和H2除发生反应I外还发生反应Ⅱ．CO2g+H2g⇌COg+H2Og． 维持压强不变按固定初始投料比将CO2和H2按一定流速通过该催化剂发生上述反应ⅠⅡ经过相同时间测得如下实验数据 表中实验数据表明升高温度CO2的实际转化率提高而甲醇选择性降低其原因是．
BroadBand:byClaireL.Evans.Portfolio2018﹩27 Thoughoftenoutnumberedbymenwomenstayedintheboomingfieldofcomputing.InthisinspiringtalewriterEvansrecordsthecontributionsofsomeofthemanywomenwhoaidedtheriseofthemodernInternet. MemorablecharactersincludeElizabethJakeFeinleraninformationscientistwhohelpedresearchersnavigatetheArpaneandStacyHornwhostartedoneofthefirstsocialnetworksEcho. TheWizardandtheProphet:byCharlesC.Mann.Knopf2018﹩28.95 Thehumanpopulationismovingtoward10billion﹣﹣﹣someexpertsthinkwe'llnearlyhitthatmarkby2050.Howwilltheearthfeedhouseandotherwisesupportsuchacrowd?Environmentalthinkersusuallyfallintooneoftwocamps:thosewhopreferconservationandcontrollingconsumptionlikeWilliamVogtandthosewhotrustinnovationtosolveourproblemsNormanBorlaugforexample.WriterManncarefullyrecordsthelivesandthoughtofthefoundersofthesetwophilosophies. ALabofOne'sOwn:byPatriciaFara.OxfordUniversityPtess2018﹩24.95 InWorldWarImanywomenintheU.K.replacedtheirapronswithchemicalsuitsandsteppedintopreviouslymale﹣onlyfieldsofsciencewheretheyledwarresearchefforts.SciencehistorianFaraillustratesthelivesofmanyoftheseforgottenwomen.Althoughtheeramarkedamajorstepforwardforwomenscientistsmanyworkedforsmallwagesinanenvironmentofdiscrimination. Inthenearly100yearssincewomenhavecomealongwayFarawritesbuttheglassceilingsremainsolidandthepipelinesleaky. AtomLand:byJonButterworth.TheExperiment2018﹩19.95 Butterworthtakesreadersonanamusingjourneythroughtheunknownworldofparticle粒子physics.ThefirststopisAtomLandwhereButterworthexplainshowelectronsprotonsandneutronscometogethertobuildupeverythingweknow.Asthejourneyunfoldswelearnaboutlesser﹣knownparticles.Thankfullyourshipisequippedwithtoolssuchasmathematicalequations方程式andalaserlightthatlightsupthedarkestofconcepts. 1Whofocusesonthefutureofourearth? A.ClaireL.Evans. B.CharlesC.Mann. C.PatriciaFara. D.JonButterworth. 2Whichbookswillyouprobablyreadifyouareinterestedinwomen'scareer? A.BroadBand&AtomLand. B.TheWizardandtheProphet&AtomLand. C.BroadBand&ALabofOne'sOwn. D.ALabofOne'sOwn&AtomLand. 3What'sthepurposeofwritingthepassagesabove? A.Toclarifysomeconcepts. B.Tointroducesomefamouswriters. C.Tomakecommentsonsomebooks. D.Torecommendsomebooks.
Asnowstormhitmyneighborhoodtheotherday.Ihadrecentlyagreedtobethehouse'sgroundskeeperwhichmeantIgot1withshoveling铲theinchesofsnowthatcoveredthedriveway. Ihadstayedinthehouseduringthe2soIwasactuallyprettyhappytohead3.IshoveledforanhourorsoandIfeltmusclesinmyarmsandlegsthatIhad4usedstarttoburn.BythetimeIfinishedshovelingIwasgettingthe5Inormallygetfrombiking.TobehonestIwaspretty6tostop. AfewdayslatersomefriendsandIgotintoa7abouthowharditistoexercise.Goingtogymsisbecomingthemostannoying8ever.Notexercisinghasaneffectonourhealth.Lessthan5%ofadultsarephysically9forhalfanhouraday.Notexercisingenoughcan10diseaseslikeheartdiseasescancerobesityanddepression. Andyetshovelingsnowwasthat11.Itdidn'ttaketoomuch12becauseIwasn'tshovelingforexercisebutto13thedriveway.Peoplepaymuchmoneyforgymmembershipsandclassesto14extrafat.Sowhynot15payingthefitnessindustrytoexerciseandhelpwitheachotherwithsuchkindof16?Surelythey'rebetteroff17thatmoneyandputtingtheenergytopracticaluse. AneighborhoodcouldhaveaFacebookgroupwherepeoplecould18thingstheyneededhelpwith.Thenpeoplewhowantedtoexercisecould19.Win﹣win.Insteadofmakingitabouthelpingpeopleitcanbeframedasanewfitness20. 1A.charged B.filled C.tasked D.crowded 2A.festival B.disaster C.rush D.storm 3A.outside B.inside C.forward D.backward 4A.usually B.directly C.really D.rarely 5A.challenge B.exercise C.threat D.power 6A.lucky B.angry C.happy D.sorry 7A.party B.meeting C.discussion D.fight 8A.homework B.routine C.solution D.business 9A.strong B.healthy C.active D.sleepy 10A.bringabout B.setoff C.takedown D.livethrough 11A.difficult B.easy C.valuable D.perfect 12A.determination B.intelligence C.reputation D.confidence 13A.design B.clear C.build D.wash 14A.puton B.passdown C.pickup D.burnoff 15A.enjoy B.miss C.stop D.escape 16A.reality B.labor C.dream D.faith 17A.saving B.collecting C.donating D.achieving 18A.seek B.imagine C.post D.examine 19A.helpout B.showoff C.turnaround D.runaway 20A.lesson B.skill C.map D.style
已知F为双曲线Ca＞0b＞0的左焦点直线l经过点F若点Aa0B0b关于直线l对称则双曲线C的离心率为
若xy满足约束条件目标函数z＝ax+y取得最大值时的最优解仅为13则a的取值范围为
ClO2是一种优良的消毒剂浓度过高时易发生分解常将其制备成NaC1O2固体以便运翰和贮存．过氧化氢法制备NaC1O2的实验装置如图甲所示． 已知①2NaClO3+H2O2+H2SO4═2ClO2↑+O2↑+Na2SO4+2H2O． ②ClO2的熔点为一59℃沸点为11℃H2O2的沸点为150℃ ③当沮度低于38℃时NaClO2饱和溶液中析出的晶体是NaC1O2•3H2O．当温度在38﹣60℃时析出NaC1O2温度高于60℃时NaC1O2分解． 请回答下列问题 1当仪器组装完毕后有同学认为关闭弹簧夹K1和K2取下X上端的玻璃塞加入一定量的水后塞上玻璃塞再打开X下端的活塞可以检查装置的气密性．请判断该方法能否检查装置气密性并说明理由 2Cl﹣对ClO2的生成有一定催化作用．反应开始时在三颈烧瓶中加入少量盐酸ClO2的生成速率会大大提高并产生微量氯气．该过程经两步反应完成将其补充完整． ①用离子方程式表示 ②H2O2+Cl2═2C1﹣+O2+2H+． 3C中将装置浸入冰水浴中的作用是． 4若实验室采用如图乙所示的装置从C中的溶液中获得NaClO2晶体．则需要在该装置的Y处增加一个设备． ①采用上述装置浓缩NaClO2溶液的操作称为． ②水浴加热的温度最好控制在℃左右填序号． A.40B.55C.70D.100 ③装置中毛细玻璃管的作用是． ④当蒸馏烧瓶中出现大量晶体后填操作．用38﹣60℃热水洗涤晶体干操后得到产品． 5产品纯度的测定称取mg产品配成250mL溶液取25.00mol•L﹣1溶液加入足量的KI和稀H2SO4充分反应后加入指示剂用cmol•L﹣1Na2S2O3标准溶液滴定至终点I2+2S2O32﹣═2I﹣+S4O62﹣平均消耗标准溶液的体积为VmL则产品中NaClO2的质量分数是%．
假设你是李华得知你的英国好友Tom通过了来华支教的申请将于今年七月到边远地区教学.请根据下面的提示给他写封电子邮件: 1.表示祝贺; 2.分析可能遇到的挑战; 3.告知提前了解当地的风俗习惯. 注意: 1.词数100左右; 2.可以适当增加细节以使行文连贯.
文中共有10处语言错误每句中最多有两处每处错误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. MyfriendLillyandIwereonthewaybacktohomefromschoolwhenwesawaboyfalloffhisbicycles.Theboylayonthegroundscreamedinpain.Werushedtohelpandfoundiftheboy'sleftlegwasbleeding.Ithappenedthatwehavelearnedsomeknowledgeaboutfirstaidbeforesoweknewhowweshoulddo.Wedialed120andcalledanambulance.WhilewaitingitItookoutmyhandkerchiefandpressedthemontothebleedingpoint.Thenwerolledtheboyontoonesidebutputhimintherecoveryposition.Westayedwithhimuntiltheambulancearrived5minuteslate.
在等比数列{an}与等差数列{bn}中a1＝1b1＝﹣2a2+b2＝﹣3a3+b3＝﹣4． 1求数列{an}与数列{bn}的通项公式 2若cn＝an+bn求数列{cn}的前n项和Sn．
AprojectinGambiaisempoweringwomenandreducingdangerouswasteatthesametime. TheWasteInnovationCenterfundedbytheEuropeanUnion'sGlobalClimateChangeAllianceshowswomenintheBrikamaareahowtorecyclewasteintousefulmaterialsandproductswhichtheycanthensellinlocalmarkets. Wood﹣likewasteisrecycledintocharcoal木炭forexamplewhichcanbeusedtosupersedefirewoodandreducethenumberoftreesthatarecutdownforfirewood.Foodwasteisrecycledintocompost混合肥料tofunctionasenvironmentallyfriendlyfertilizersandplasticisturnedintomanyusefulthings. SupportedbyWasteAidUKandtheGambiaWomen'sInitiativeGWIamongotherstheprojectprovideswomenwithskillstheycanusetobecomeself﹣sufficient自给自足的.Womenlearningatthecentercomefromfivecommunitiesandsomeofthemtravelasfaras12milestolearntheseimportantskillsthatwillprovidethemwithanincomeaccordingtoTheGuardian. IsatouCeesaywhonowleadstheGWIhighlightedtheneedtofocusoneconomicequalityinhercountrytellingTheGuardianIntermsofeducationwomenaretheoneswhoarealwaysbehind.Boysarechosentogotoschool.Whenweconductourtrainingwefindwomencandoalotbutdon'tknowwhotheyareorhowtoimplement实施things. AccordingtotheWorldHealthOrganization'sCountryCooperationStrategy2008﹣2013reportthemainenvironmentalissuefacingGambiaispoorwastemanagementinurbanareas. NdeySirengBakurinexecutivedirectoroftheNationalEnvironmentAgencyhasvoicedconcernoverhealthandenvironmentalriskssuchaswaterpollutiontheincreaseofinsectsaswellasfloodingthatoccurasaresultofpoorwastemanagement. 1WhatdoestheWasteInnovationCentertrytodo? A.DeveloplocalmarketsinBrikama. B.Teachwomenhowtoinventnewthings. C.Keepwomenawayfromdangerouswaste. D.HelpwomeninBrikamabenefitfromwaste. 2WhatdoestheunderlinedwordsupersedeinParagraph2probablymean? A.Replace. B.Transform. C.Burn. D.Reserve. 3FromwhatIsatouCeesaysaidwecanlearnthatwomeninGambia. A.don'tlearnnewthingsfast B.aren'tinterestedineducation C.reallyhopeforeconomicequality D.arenotfairlytreatedinthecountry 4Whatisthewriter'spurposeofwritingthelastparagraph? A.Tosummarizethepreviousparagraphs. B.Toprovidesomeadviceforthereaders. C.Toaddsomebackgroundinformation. D.Tointroduceanewtopicfordiscussion.
ItwasapainfultimeformeforIsufferedfromanillnessandmightneverbeabletohaveachild.Asmy40thbirthdayapproachedIbeganforthefirsttimetonoticebabiesandtheirhappysmilingmotherswhereverIwent. OnenightIcametoacafetokilltheboringtime.Anelegantlydressedsightlyolderwomanwasseatednexttome. Wouldyouliketoseeapictureofmydaughter?sheaskedmehandingmeaphotoofasmilingChinesegirl.ThechildwasaboutsevenyearsoldandwaswearingaSnowWhitecostume.That'sMelanienowinthefirstgradeshesaid.Icouldhearthemotherlyprideinhervoice.She'sprettyIsaid.Ilovehercostume.ThewomanexplainedthatshefeltstronglyaboutteachingherdaughteraboutChinesecustomsandmaintainingtiestohershoes.Whatmadeyoudecidetoadopther?Iasked.Ididn'twantworktobemywholelifeshesaid. I'mnotsureifshesawthetearsinmyeyesasIrepliedIdon'teitherbutI'mafraidit'stoolate.Iwas51whenIadoptedMelanieshesaid.Andit'sthemostrewardingexcitingthingI'veeverdone. WhenmyhusbandandIreturnedfromChinawithournine﹣month﹣olddaughterMadelineinNovember2017JillwasoneofthefirstpeopleIe﹣mailed.Ididit!Iwrote.I'mamotherandshe'sbeautiful Congratulationsshewroteback.WerecentlyreconnectedonFacebookandItoldherYouchangedmylife. 1WhatcanbeinferredfromParagraph1? A.Theauthorregrettedhermarryingtooearly. B.Theauthorwasrecoveringfromaseriousdisease. C.Theauthordidn'thaveachildofherownduetosomeillness D.Theauthorhadbeeneagertobeahappymotherforalongtime. 2WhichwordscanbestdescribeJillaccordingtoParagraph3? A.Elegantandgenerous. B.Caringandconsiderate C.Friendlyanddetermined. D.Practicalandindependent 3Whatcanwelearnabouttheauthorfromthetext? A.Shewouldn'tdevoteherwholelifesimplytowork. B.SheappreciatedthepicturedrawnbyMelanie C.Herhusbandwasagainstheradopting. D.HerdreamwaseventuallyrealizedinthecompanyofJill 4Whatintheauthor'spurposeinwritingthetext? A.Tostresstheinfluenceofthekindness B.Toshowusthehiddenbeautyinourworld C.Tocallonustoadoptmorehomelesschildren D.Tosharehermeaningfuladoptionstorywithus.
国家放开计划生育政策鼓励一对夫妇生育2个孩子．在某地区的100000对已经生育了一胎夫妇中进行大数据统计得有100对第一胎生育的是双胞胎或多胞胎其余的均为单胞胎．在这99900对恰好生育一孩的夫妇中男方女方都愿意生育二孩的有50000对男方愿意生育二孩女方不愿意生育二孩的有x1对男方不愿意生育二孩女方愿意生育二孩的有x2对其余情形有x3对且x1x2x3＝30010099．现用样本的频率来估计总体的概率． 1说明“其余情形”指何种具体情形并求出x1x2x3的值 2该地区为进一步鼓励生育二孩实行贴补政策凡第一胎生育了一孩的夫妇一次性贴补5000元第一胎生育了双胞胎或多胞胎的夫妇只有一次性贴补15000元．第一胎已经生育了一孩再生育了二孩的夫妇一次性再贴补20000元．这种补贴政策直接提高了夫妇生育二孩的积极性原先男方或女方中只有一方愿意生育二孩的夫妇现在都愿意生育二孩但原先男方女方都不愿意生育二孩的夫妇仍然不愿意生育二孩．设ξ为该地区的一对夫妇享受的生育贴补求Eξ．
Doyoulikewritingafewparagraphseverydayaboutyourexperienceshopesmemoriesorfeelings?Ifyoudon'tit'stimetomakeachangenow.Writejustafewparagraphseverydayaboutyourexperienceshopesmemoriesandfeelingsandyouwillimmediatelybegintoexperiencebenefitstoyourpersonalgrowthandpotential. Youwillgraduallybecomebetteratexpressingyourself.1Howeverwhenyoubecomelazywithwordsyoufinditismoredifficulttodescribefeelingsshareexperiencesandmakeyourselfunderstood. 2Asyouwriteaboutmemoriesitislikeopeninganoldphotoalbum.Yourpenbeginstoexplorefeelingsanddetailsyouhaveforgottenanddreamsyouhaveleftbehind.Yousuddenlyrememberpeopleyouwouldliketocontactagain.Writingisanactivitythatavoidsdistraction使人分心的事longenoughforyoutoexplorethosewonderfulmomentsofthepast.Sometimestheyarefrightening3 Writingaboutdailyexperiencesandfeelingsprovidesarecordedhistorythatwillinfluencehowyoumakefuturedecisions4Theylearnedfromwhathadhappenedbefore.Yourhistoryisimportant.Don'tletitbeforgotten. Writingremindsyouofyourdreamsandkeepsyoumovingtowardthem.Itisameansofkeepingtrackofyourpurposeandthegoalsthatwillleadyoutoachievethem.5Itshowswhenyouhavebeendistractedandmayneedtogiveallyourattentionagaintoyourwriting. Writingalittleeverydaycouldprovidethematerialthatsomedaybecomesapublishedbook.WhenIwroteaboutmydepressionandmyfour﹣year﹣oldgranddaughterwhogotlostinthemountainsIneverdreameditwouldbeinabook. A.Youwillrememberthingslongforgotten. B.Writingkeepsyouenergeticandfullofimaginationallthetime. C.Sometimestheyarewonderfulandalmostalwaystheyarehelpful. D.Soonerorlateryouaresurelytobecomeagreatprofessionalwriter. E.Reviewingwhatyouhavewrittenisaperfectwaytoseeyourprogress. F.There'sareasonthatthegreatestleadersinhistorywerestudentsofhistory. G.Whenyouwritedailyyoucanalwaysbeamazedathowquicklyyourwritingskillsimprove.
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. RecentlywehavehadainstructivediscussiononhowtomakeEnglishlearningrelaxingandinteresting.It'salltoonaturalthatwehadcomeupwithalotofadvicesconcerningthetopic.FirstlywecanhavemoreinteractiveactivitiesthatmakesEnglishlearninggreatfuninclassanditisgenerallyconsiderednotalittlebeneficiallytousall.SecondlyweneedtofindmorechancestocommunicatingwithpeopleinEnglishwhethertheyareEnglishteachersandclassmatesbecauseusingEnglishisthebestwaytolearn.Asitisknowntoallpracticemakesperfect. InmyeyestherearemanyotherwayslikelisteningEnglishsongswatchingEnglishmoviesjoiningEnglishclubsormakingpenfriendsontheInternet.Thatweneedmostismoretimeandmorespace.
i是虚数单位＝
假设东莞市市民使用移动支付的概率都为p且每位市民使用支付方式都相互独立的已知X是其中10位市民使用移动支付的人数且EX＝6则p的值为
设1﹣im＝1+ni其中mn是实数则|m﹣ni|＝．
设0＜p＜1随机变量ξ的分布列是 则当p在01内增大时
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