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某涂料添加剂M的成分为银、铝、锌中的一种，为确定其成分，取一定质量的M和稀硫酸进行实验． ①银、铝、锌的金属活动性由强到弱的顺序是 ． ②用如图1方法收集氢气，是因为氢气 （选填“可溶...
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有一种纳米润滑添加剂由铝粉铜粉氧化铝粉末中的一种或几种组成取少量该添加剂加入足量稀盐酸有红色固体残
该添加剂中一定有铜，可能有铝和氧化铝
若向滤渣中加入足量稀盐酸，滤渣部分溶解，则该添加剂中一定有氧化铝
滤渣中一定有银和铜，滤液中一定有硝酸铝和硝酸铜
滤液中最多含有三种溶质
食品营养强化—根据不同人群的营养需要向食物中添加一种或多种营养素或某些天 然食物成分的食品添加剂用以
计算题某药物添加剂在配合饲料中允许使用量为4mg/kg该饲料添加剂商品含有效成分为4%试计算该添加剂
氧化锌是一种常用的化学添加剂广泛应用于药膏阻燃剂等产品的生产中由锌灰主要成分是Zn生产活性ZnO的部
是一种扩展了的添加剂预混料其核心成分除了各种添加剂外还包括等常量矿物元素
汽车涂料一般由成膜物质颜料添加剂和等4种基本成分组成
溶剂
快干剂
固化剂
催化剂
有一种纳米材料添加剂由铝粉氧化铝粉末铜粉中的一种或几种组成为探究该添加剂的成分化学学习小组进行了下列
二烷基二硫化磷酸锌是一种常用的极压性添加剂添加量在6%以下
固态粉粒的氯化胆碱添加剂的有效成分为
有一种纳米润滑添加剂由铝粉铜粉氧化铝粉末中的一种或几种组成取少量该添加剂加入足量稀盐酸有红色固体残留
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MMT作为加入汽油中的一种添加剂其作用主要是提高汽油的性能该添加剂属于一种填金属名称剂该剂具有见光容
有一种纳米润滑添加剂由铝粉铜粉氧化铝粉末中的一种或几种组成取少量该添加剂加入足量稀盐酸有红色固体残留
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涂料的组成分包括哪些
颜填料
树脂
溶剂
添加剂
在学习了金属的化学性质后科学老师布置了一项课外学习任务调查化工颜料店出售的涂料添加剂银粉是什么金属某
根据不同人群的营养需要向食物中添加一种或多种营养素或某些天然食物成分的食品添加剂用以提高食品营养价值
下列关于食品添加剂的叙述正确的是
食品添加剂是指为改善食品品质和色、香、味，以及防腐和加工工艺需要而加入食品中的化学合成物质
食品添加剂均为化学合成物质，无天然成分
复合食品添加剂是指由两种以上单一品种的食品添加剂经化学合成的食品添加剂
复合食品添加剂是指由两种以上单一品种的食品添加剂经物理混匀而成的食品添加剂
食品添加剂是指为改善食品品质和色、香、味，以及防腐和加工工艺需要而加入食品中的化学合成或天然物质
铸造铝合金生产首先要知道和对杂质的要求
合金的成分
变质剂
添加剂
涂料
在学习了金属的化学性质后科学老师布置了一项课外学习任务调查化工颜料店出售的涂料添加剂银粉是什么金属某
涂料的组成一般有四种基本组成分组成溶剂和添加剂
有一种纳米润滑添加剂由铝粉铜粉氧化铝粉末中的一种或几种组成取少量该添加剂加入足量稀盐酸有红色固体残留
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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
Flyingdowna488﹣meter﹣longslideprovidesplentyofexcitementformostpeople.ButforthosewholikemoreextremeadventuresNicaraguaoffersanevenmoreexcitingslideexperience.Thethoughtofracingdownanactivevolcanowithonlyaboardisenoughtogetmostpeoplehotunderthecollar.Butforthrill﹣seekingsportsfanaticsboardingdowna2380﹣foot﹣highvolcanoatthespeedof80km/histhecoolestsportaround. ThousandsoftravelersareheadingtothefoothillsofNicaragua'sCerroNegrototakepartinthenewsportingcraze狂热.Surfersdressedinprotectivejumpsuitsknee﹣padsandhelmetsreceivebriefinstructionsandthentryslidingdownashortslope斜坡.Afterthatit'stimefortherealthing. Sittingontheirspecially﹣constructedboardssurferspushoffandflystraightdowna488﹣meter﹣longslope.Theblackvolcanicashprovidesadustydirtyride.Butboardersusuallyarriveatthebottomwithsmilesontheirfaces. PhillipSouthanownerandmanagerofBigfootHostelandGreenPathwaysTourssaidWestartedofferingthistripin2005andithasbecomesopopular.Thisisauniquetourasnowhereelseintheworldcanyouboarddownanactivevolcano. Whatweofferisatourforeveryonewithabsolutelynoexperience.Oneofthegreatestattractionsofthetouristhatyougetabitofeverything.Since2005morethan10000peoplehavetraveledtoCerroNegrotogiveitatry. Whenyouareonthetopyouwillhavetheopportunitytostandnearthecrater火山口andseeasmokingvolcano.Butthebiggestriskisthatyouwilltakethechanceofgettingsomescratchesifyoufallover. Manyyearsofexperiencehastakenthistourtoalevelwhereitissafebutstillfunandforsomepeoplealittlefrightening.Wearealwaysworkingonwaystocontinueimprovingitforthefuture. 1WhichwordscanbestdescribetheslideinCerroNegro? A.Securebuttiring. B.Enjoyablebutrisky. C.Popularbutdemanding. D.Worthwhilebutpainful. 2Whatdoestheunderlinedwordstherealthinginparagraph2referto? A.Slidingdownthevolcanicslope. B.Escapingtheblackvolcanicash. C.Headingtothemountaintopalone. D.Receivingprofessionalslideinstructions 3InwhatwayistheslideinCerroNegrospecial? A.Itisavailabletoeveryone. B.Ithasthelongestslopeworldwide. C.Itisbasedonanactivevolcano. D.Itoffersspecially﹣constructedboards. 4WhatmakestheslideinCerroNegrorelativelysafeaccordingtoPhillipSouthan? A.High﹣techsafetyfacilities. B.Knowledgeandskillsfrompractice. C.Advancedtrainingguidanceontheslide. D.Staff'sfamiliaritywiththesurroundings.
Webelievethatthemoreyougetoutintotheworldthebetterplaceit'llbe.Butgettingoutintotheworldshouldn'tmeanleavingafootprint.1Byfollowingthoseyourdestinationwillbebetterafteryouleave. Don'tholdback.Thebestwaytoknowanewplaceistotalktothelocalpeople.Whenyou'restayingwiththemtellthemaboutwhoyouarewhyyou'retherewhatyouwanttoseeandwhatyouloveaboutbringingyourselftonewplace.2. Diverightin.What'sthepointintravellingoutsideofyourhomecountryifyoudon'talsogetoutofyourcomfortzone?3Ifyouwanttoskydiveandjusthavehadthatchancedoit.You'llgohomewithastoryandwillleavelocalswithastoryoftheirownofabravetravelerwhoconqueredtheirfears. Doyourhomework.4Trytolearnmoreaboutlocalcustomstraditionsandmannerssothatyou'llarrivewellequippedtoenjoyyourtimeandcommunicatewithlocalswithoutanybadimpressions. 5Wealltravelfordifferentreasons.Don'tforgetwhatdroveyoutohittheroad.Sometimesthebestmemorieshappenwhenyouleastexpectthem.Ifyouopenyourselfuptotheworldyou'llneverknowhowtheworldwillchangeyou! A.Stayhonestbutgetopen B.Travelwhenyou'reeagertotravel. C.Don'tdoanythingthatyoumightregret. D.There'snobetterwaythanbringabitofyourselftoit. E.Hereareseveralwaystomakeyourmarkwhileyou'retravelling. F.Sometimesit'sbesttobearmedwithknowledgeaboutyourdestination. G.Youshouldn'ttakemanyfactorsintoconsiderationwhenchoosingyourdestination.
假定你是李华在某英文网站上看到一家国际文化机构招聘中学生暑期志愿者.请根据以下提示用英语写封自荐信.要点包括: 1.表达兴趣; 2.阐述自己的优势; 3.希望得到回复. 注意: 1.词数100左右开头和结尾已给出不计人总词数; 2.可以适当增加细节以使行文连贯. DearSir/Madam YoursSincerely LiHua
已知xy∈R则”x＞1或y＞1”是“x+y＞2”的
德国数学家科拉茨1937年提出了一个著名的猜想任给一个正整数n如果n是偶数就将它减半即如果n是奇数则将它乘3加1即3n+1不断重复这样的运算经过有限步后一定可以得到1．对于科拉茨猜想目前谁也不能证明也不能否定现在请你研究如果对正整数n首项按照上述规则施行变换后的第8项为1注1可以多次出现则n的所有不同值的个数为
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已知数列{an}中a1＝1a2＝302an＝an+1+an﹣1+2n∈N*且n≥2则数列{an}的最大项的值是
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已知函数． 1求fx的单调区间 2若直线ly＝ax+b是函数Fx＝fx+2x的图象的切线且ab∈R求a+b的最小值．
已知实数xy满足约束条件则z＝3x+y的最小值为
已知xy∈R则”x＞1或y＞1”是“x+y＞2”的
已知△ABC的内角ABC的对边分别为abc且acosB＝2c﹣bcosA． Ⅰ求角A的大小 Ⅱ若a＝6求△ABC面积的最大值．
下列函数中在区间0+∞上为增函数的是
已知正项数列{an}中a1＝1a2＝22an2＝an+12+an﹣12n≥2则a6等于
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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:在错的词下画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. TheotherdayIaswellasmyparentswereeatinginarestaurantwhenwenoticedaforeignercomingin.Heseatshimselfatatablebythewindow.Soonawaitresscameandwantedtotakeorder.Howevertheforeignercouldn'tgothisneedsacross.SeeingthisIwentupimmediatetooffersomehelps.WecommunicatedwithsimpleEnglishforawhilebutIlaterknewwhythewaitresscouldn'tunderstandhim.TheforeigneractuallywantedaroastBeijingduckbuthehadawrongChinesepronunciation.Heardmyexplanationthewaitresscouldn'thelptolaughing.Theforeignerhimselfalsolaughed.
设函数fx满足[xfx]′＝lnx且fe＝1． ①函数fx＝lnx+﹣2是满足条件的函数 ②f′e＝0 ③fx有唯一零点 ④fx的最小值为1． 以上说法正确的是
某市通过随机询问100名不同年级的学生是否能做到“扶跌倒老人”得到如下列联表 则下列结论正确的是 附参照表 参考公式其中n＝a+b+c+d
x3﹣7的展开式中x9的系数是用数字作答
WhenKevinDurantgavehistearfulMVPspeechin2014theNBAstarmadesuretothankonepersonwhohadbeentherewithhimfromtheverybeginning:hismother.HisheartfeltwordsaboutthesacrificesshemadeforDurantandhisbrotherledtoalifetimemovieaboutherjourneyasasingleparentTheRealMVP:TheWandaDurantStory. TodaytheNBAsuperstar'smomtravelsthecountryasamotivationalspeakerandphilanthropist慈善家.OnMondayshespokeatThomsonReuters'inNewYorkaboutherpersonalstrugglestoachievefinancialstabilityandsharedthefinancialadviceshegavehersonwhenheenteredtheleaguewithCNBC. IwantedhimtorealizehehasworkedhardshesaysAnditisOKforhimtoenjoyhimselfbecauseofhishardwork.Butitisalsoimperativethathepreparesforhisfuture.Whilesheadvisedhimtoenjoytherewardsofhislaborshealsowantedtomakesurethathersonknewtheimportanceoffinancialplanning. Shetoldtheaudiencethatwhenshefoundherselfasingleparenttotwochildrenat21shecouldn'tfollowthefinancialprinciples.Ratherthanplanningforthefutureshefocusedonlyonhowhermoneycouldmakeendsmeetforthatmoment. RecentlyDuranthasteamedupwithLaurenePowellJobsforanewphilanthropicprogramcalledCollegeTrackwhichisaimedathelpingdisadvantagedkidsattendcollege.AspartoftheprogramDuranthascommittedtodonating＄10milliontohishometown'spublicschoolsystem. Durant'smomsaysthatinadditiontohisfinancialdecisionssheisproudofhisphilanthropicworkandhisdesiretohelpthecommunity.Ithoughtgivingbackwasalwaysveryimportantandsowetalkedaboutthatandhehadseenthatfromusasafamilyandit'soneofthethingsthatItaughthimshesays. 1WhatisTheRealMVP:TheWandaDurantStorymainlyabout? A.Durant'scareerpath. B.Durant'shardchildhood. C.Durant'smother'sdevotiontothefamily. D.Durant'smother'sstrugglingtobeindependent. 2Whatdoestheunderlinedwordimperativeinparagraph3mean? A.Enjoyable. B.Important. C.Unusual. D.Hopeful. 3WhatarethefinancialprinciplesofDurant'smom? A.Enjoyingnowandplanningforthefuture. B.Sharingrewardsandcreatingacharityprogram. C.Spendinglessmoneyandsavingfortheemergencies. D.Donatingmoneytothecharityandhelpingmoreschools. 4WhatmadeDurantpayattentiontothecharityprogram? A.Hiskindheart. B.Hispoorhometown. C.Hismother'steaching. D.Hisdifficultlifeexperiences.
某国企进行节能降耗技术改造下面是该国企节能降耗技术改造后连续五年的生产利润 预测第8年该国企的生产利润约为千万元 参考公式及数据＝＝﹣
设ab是关于x的一元二次方程x2﹣2mx+m+6＝0的两个实根则a﹣12+b﹣12的最小值是
Forthefirsttimein10yearstheUnitedStatesgovernmenthaschangeditsguidanceonhowmuchexercisepeopleneedtostayhealthyandwhentheyshouldstart. Forchildrenandteens Thenewguidancestatesthatthemostimportanttimeforchildrentobeginexercisingisbetweentheagesof3and5.1Thatcouldbelightactivitiesmoderateactivitiesorevenvigorous剧烈的activities. Doctorssayitisimportanttostartyoung.Theyaddthatfrombirthtoage5achild'sbraindevelopsmorethanatanyothertimeinlife.2Alsochildrenwhostartexercisingatayoungagearemorelikelytoestablishhealthybehaviorstheywillcontinueintoadulthood. Butthatdoesnotmeanputtingasmallkidonatreadmill跑步机orotherexerciseequipment.3Afterallit'sakid'snaturetoplayfreelyandhappily. 4Butitshouldn'tbelessthanonehouradaythreetimesaweek.Theiractivitiesshouldmostlybeaerobic有氧的exercisesuchasbikingswimmingorrunningwhichcanstrengthentheheartandlungs.Suchexerciseshouldalsoincludemuscle﹣and﹣bone﹣strengtheningactivities;suchasclimbingtreesorplaygroundequipmentandplayingsports. Foradults Foradultstheguidelinesrecommendexercising150minutesaweek.Thatcouldbewalkinggardeningdancingetc.5Expertssaythatevenshortamountsofaerobicexercisecanprovidehealthbenefitssuchasloweringbloodpressurereducinganxietyandimprovingsleep. A.Anykindofactivitythatgetspeopleexercisingwilldo. B.Aerobicactivityworksonlyifitlastsforatleast10minutes. C.Simplygivingakidthetimeandspacetoplayactivelyisenough. D.Childrenabove5canhavearelativelyshortertimefordailyexercise. E.Childreninthisagerangerequireaboutthreehours'activeactivitiesdaily. F.Attainingthehealthbenefitsfromexercisemaybeharderthanearlierthought. G.Thesedevelopmentshavea1astingeffectonachild'sabilitytosucceedinlife.
下列函数中在区间0+∞上为增函数的是
BluePlanetII'slatestepisodefocusesonhowplasticishavingadisastrouseffectontheoceanandslowlypoisoningourseacreatures.ResearchersrecentlyalsofoundthatseacreatureslivinginthedeepestplaceonEarththeMarianaTrenchhaveplasticintheirstomachs.Indeedtheoceansaredrowninginplastic. Thoughitseemsnowthattheworldcouldn'tpossiblyfunctionwithoutplasticsconsumerplasticsarearemarkablyrecentinvention.Thefirstplasticbagswereintroducedinthe1950s;thesamedecadethatplasticpackagingbegangaininginpopularityintheUnitedStates.Thisgrowthhashappenedsofastthatscienceisstillcatchingupwiththechange.Plasticspollutionresearchforinstanceisstillaveryearlyscience. Weputalltheseplasticsintotheenvironmentandwestilldon'treallyknowwhattheoutcomesaregoingtobe.Whatwedoknowthoughisdisturbing.Oceanplasticisestimatedtokillmillionsofmarineanimalseveryyear.Nearly700speciesincludingendangeredonesareknowntohavebeenaffectedbyit.Oneinthreeleatherbackturtleswhichoftenmistakeplasticbagsforjellyfishhavebeenfoundwithplasticintheirbellies.Ninetypercentofseabirdsarenoweatingplasticsonaregularbasis.By2050thatfigureisexpectedtoriseto100percent. Andit'snotjustwildlifethatisthreatenedbytheplasticsinourseas.Humansareconsumingplasticsthroughtheseafoodweeat.Icouldunderstandwhysomepeopleseeoceanplasticasadisasterworthmentioningtothesamedegreeasclimatechange.Butoceanplasticisnotascomplicatedasclimatechange.Therearenooceantrashdeniers否认者atleastsofar.Todosomethingaboutitwedon'thavetoremakeourplanetenergysystem. Thisisnotaproblemwherewedon'tknowwhatthesolutionis.Weknowhowtopickupgarbage.Anyonecandoit.Weknowhowtodispose处理ofit.Weknowhowtorecycle.Wecanallstartbythinkingtwicebeforeweusesingle﹣﹣﹣﹣useplasticproducts.Thingsthatmayseemordinarylikeusingareusablebottleorareusablebag﹣﹣﹣﹣whentakencollectivelythesechoicesreallydomakeadifference. 1Whyisplasticspollutionresearchstillaveryearlyscience? A.Theplasticspollutionresearchistoodifficult. B.Plasticshaveproducedlesspollutionthancoal. C.Theworldcouldn'tpossiblyfunctionwithoutplastics. D.Plasticshavegainedinpopularitytoofastforsciencetocatchup. 2HowdidtheauthorsupporthisopinioninParagraph3? A.Bystatistics. B.Byquotationsfromleadingexperts. C.Byusingexamplesfromhisownexperience. D.Bycomparisonandcontrast. 3Whatcanweinferaboutclimatechange? A.Climatechangeiscausedbyhumanactivities. B.Somepeopleholdsomedoubtsaboutclimatechange. C.Climatechangeislessimportantthanoceanpollution. D.Oceanplasticismorecomplicatedthanclimatechange. 4Whatisthemainideaofthispassage? A.Oceanplasticisaglobalissue. B.Theoceansbecomechokedwithplastic. C.BluePlanetIIhasleftviewersheartbroken. D.Plasticsgaininpopularityallovertheworld
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