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在生产实践中,通常向果汁中加人固定化酵母细胞来生产果酒.请回答下列相关问题: (1)在制备固定化酵母细胞时,实验中的海藻酸钠的作用是 ,CaCl2的作用是 .加热溶解海藻酸钠时要特别注意用...
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高三下学期生物《》真题及答案
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葡萄酒葡萄汁是日常生活中常用的一类饮料在旱酸性的果汁发酵液中红葡萄皮的色素也会进入发酵液中且有酸碱指
在生产实践中木材表面的不平度主要是凭工人的生产经验采用或手摸的方法
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39.【生物—选修1生物技术实践】15分请回答有关果酒制作及固定化细胞的问题⑴葡萄汁发酵后是否有酒精
喷头转速与产量的关系是在生产实践中摸索出来的
在生产实践中通常粗选采用较稀的矿浆精选采用较浓的矿浆
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在生产实践中甘薯葡萄月季菊杨柳的栽培常用的方法
08汉沽一中第四次月考生物技术实践15分葡萄酒葡萄汁是日常生活中常用的一类饮料在呈酸性的果汁发酵液中
请回答有关果酒制作及固定化细胞的问题1葡萄汁发酵后是否有酒精产生可用________来检验若在酸性条
何谓细胞全能性它在生产实践中有何意义
葡萄酒葡萄汁是日常生活中常用的一类饮料在呈酸性的果汁发酵液中红葡萄皮的色素也会进入发酵液中且有酸碱指
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25分假如你是__.你收到了你在英国的笔友Charlie的来信他在信中询问你的暑假计划请就你的暑假计划给他写一封回信 1.表示收到来信的心情 2.去乡下看望祖父母 3.去电脑培训中心学电脑时间为一星期 4.读一些英语书籍但不知该读那些请对方提些建议 5.向对方父母问好盼望回信. 注可适当增加内容词数为100左右 DearCharlie Howareyou? Yours LiQiang
用3种不同颜色给2个矩形随机涂色每个矩形涂且只涂1种颜色则2个矩形颜色不同的概率为
10分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短文.短文中共有10处错误每句中最多有两处.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∧并在此符号下面写出该加的词. 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. Buildingagoodrelationshipwithourteachersbenefitusall.Teachersshowedloveconcernandunderstandforusstudentsinstudyandlife.Westudentscanalwaysseeksupportandadvicefromus.InthiscaseanidealrelationshipisofVitalimportant.Inmyopinionthisrelationshipshouldbeonefillingwithloveandrespectsowecanexchangeideasfreewithteachers.Ifwestudentstrustteachersandexpressourfeelingsclearlyortheywillbecomeourfriend.Onlythroughconstanteffortsweenjoyawarmrelationshipbetweenteachersandstudents.
已知2﹣iz=2ii为虚单位则复数在复平面上所对应的点在
已知组数据x1x2…xn的平均数为2方差为5则数据2x1+12x2+1…2xn+1的平均数与方差s2分别为
设函数. 1求fx的单调区间 2若对于任意x1x2∈[﹣mm]m>0都有|fx1﹣fx2|≤e﹣1求m的取值范围.
i是虚数单位则的虚部是
若函数fx=a=f2b=f3c=f5则
8分My3﹣year﹣oldsonandIlivedaveryhardlifebecauseIhadbeenoutofworksincetwoyearsago.Beingpoorisaterriblefeelingwhenyour3﹣year﹣oldfinisheshismealandsaysCanIhavesomemorebreadandjampleaseMummy?Andyoubreakdownintearsbecauseyoudon'tknowhowtotellhimthatthereisnomorefood.With£6Iwenttothesupermarketpickedupsomefoodandstartedtocookathome.Itwastimeformetomakeachangeandgetbackonmyfeet.IbegantowriteaseriesofarticlesforthewebsitenamedHungerHurtinJuly2011. Afewmonthslaterlocalfoodbankgavemesomehelp﹣﹣withsomefreevegetableseverymonthwhichmademylifealittleeasier.Ibegantowriterecipespostingthemonmyblog.Tomysurprisefamiliesstudentsandthosepoorpeopletoldmehowmuchithelpedtoseehealthyrecipesmadefromaffordablesupermarketvegetables. MyLifetookunexpectedturns.IwasinvitedtogiveaspeechonfoodinterviewedforanOxfamreportonfoodbanksandaskedtowriteacookerybook. WhenIgotthemoneyfromthebookforthefirstnightinalmosttwoyearsIwenttobedwithoutworrying.NowIhaveawell﹣paidjobandabeautifulhomeandI'llneverforgetthedayswhenIworkedhardforagoodlife. 1Thewriterstartedtocookbecause. A.thefoodatthesupermarketwasunhealthy B.shewasadvisedtodosobysomeone C.shehadtofeedthemselvesinacheapway D.hersonpreferredhome﹣cookedfood 2Accordingtothetextthefoodbank. A.helpssellthefoodinsupermarkets B.bringspeopletogetherwhocareaboutfoodwaste C.givesoutfoodtothosepeoplewhoareinneed D.writehealthyrecipestofoodloversaroundtheworld 3Thewriter'sfirstpostofrecipes. A.attractedonlyhousewives B.wasgivenlittlenotice C.movedthereaders D.drewmuchattention 4Whichcouldbethebesttitle? A.Successliesinyourownhands B.Alessonhardlifeteachesme C.Amother'sdreamjob D.whatalovingmother
已知abc分别为△ABC内角ABC的对边试从下列①②条件中任选一个作为已知条件并完成下列12两问的解答 ①= ②2ccosC=acosB+bcosA. 1求角C 2若c=a+b=求△ABC的面积.
若正四棱谁的所有棱长都相等则该棱锥的侧棱与底面所成的角的大小为.
8分Someofthebestresearchondailyexperienceisrootedinratesofpositiveandnegativeinteractionswhichhasprovedthatbeingblindlypositiveornegativecancauseotherstobefrustratedorannoyedoreventotuneout. Overthelasttwodecadesscientistshavemaderemarkablepredictionssimplybywatchingpeopleinteractwithoneanotherandthenscoringtheconversationsbasedontherateofpositiveandnegativeinteractions.Researchershaveusedthefindingstopredicteverythingfromthelikelihoodthatacouplewilldivorcetothechancesofaworkteamwithhighcustomersatisfactionandproductivitylevels. Morerecentresearchhelpsexplainwhythesebriefexchangesmattersomuch.Whenyouexperiencenegativeemotionsasaresultofcriticismorrejectionforexampleyourbodyproduceshigherlevelsofthestresshormonewhichshutsdownmuchofyourthinkingandactivatesconflictanddefensemechanisms机制.Yousupposethatsituationsareworsethantheyactuallyare. Whenyouexperienceapositiveinteractionitactivatesaverydifferentresponse.Positiveexchangesincreaseyourbody'sproductionofoxytocin后叶催产素afeel﹣goodthatincreasesyourabilitytocommunicatewithcooperatewithandtrustothers.Buttheeffectsofapositiveoccurrencearelessdramaticandlastingthantheyareforanegativeone. Weneedatleastthreetofivepositiveinteractionstooutweigheveryonenegativeexchange.Badmomentssimplyoutweighgoodones.Whetheryou'rehavingaconversationkeepthissimpleshortcutinmindAtleast80percentofyourconversationsshouldbefocusedonwhat'sgoingright. Workplacesforexampleoftenseethis.Duringperformancereviewsmanagersroutinelyspend80percentoftheirtimeonweaknessesandareasforimprovement.Theyspendroughly20percentofthetimeonstrengthsandpositiveaspects.Anytimeyouhavediscussionswithapersonorgroupspendthevastmajorityofthetimetalkingaboutwhatisworkingandusetheremainingtimetoaddressweaknesses. 1TheunderlinedphrasetuneoutinParagraph1probablymeans. A.gaincourage B.stoplistening C.singaloud D.feelstressed 2Whatwillhappenifyouexperiencenegativeemotions? A.Muchofyourthinkingwillbeprevented. B.Thesituationsaresuretobecomeworse. C.Youwillfeelanurgetoimproveandbecomebetter. D.You'llbemotivatedtoresolveconflictswithpeople. 3FromParagraph4wecanlearnthat. A.weneedapositivefeelingtobeatonenegativefeeling B.theeffectofnegativefeelingslastslongerthanthatofpositiveones C.ourconversationshouldcenteronwhatneedsimprovement D.positiveinteractionshavegreatereffectsthannegativeones 4Whatisthebesttitleforthepassage? A.HarmfulNegatives. B.LessTimeonStrengthsandPositiveAspects. C.HowtoBeaProductiveManager. D.MorePositiveInteractions.
要设计一容积为π的下端为圆柱形上端为半球形的密闭储油罐已知圆柱侧面积的单位面积造价是下底面的单位面积造价的一半而顶部半球的单位面积造价又是圆柱侧面积造价的一半储油罐的下部圆柱的地面半径R=时造价最低.
两直角边分别为1的直角三角形绕其斜边所在的直线旋转一周得到的几何体的表面积是
△ABC中===在下列命题中是真命题的有
土笋冻是闽南种广受欢迎的特色传统风味小吃某小区超市销售一款土笋冻进价为每个15元售价为每个20元.销售的方案是当天进货当天销售未售出的全部由厂家以每个10元的价格回购处理.根据该小区以往的销售情况得到如图所示的频率分布直方图 1估算该小区土笋冻日需求量的平均数同一组中的数据用该组区间的中点值代表 2已知该超市某天购进了150个土笋冻假设当天的需求量为x个x∈N0≤x≤240销售利润为y元. i求关于x的函数关系式 ii结合上述频率分布直方图以额率估计概率的思想估计当天利润y不小于650元的概率.
求证
15分MemorizinghundredsofEnglishwords1bealwaysabigheadacheforstudents.Whynotlet2amazingappBaicizhanhelpyou?Firstofalltheapphelpsyoudivideyourworkintodailytasks.3youhavechosenthevocabularylistandanenddatetheappthenquicklytellsyouhowmanywordsyouneedtolearneveryday.Forexampleyoucanspendjust10minutes4memorize15wordseveryday.Doesn'tthatsoundmuch5easythantryingtodoeverythingatonce?That'snotall﹣itcanalsobemuchfun.Thelearningprocessislikeplayingaguessinggame.Instead6justshowingtheChineseandEnglish7meaningofanewwordtheappasksyoutofirstchoosethecorrectpicturefromfour8baseonanEnglishdescription.Thishelpsyoumemorizethewords9clear.AndalloftheEnglishisreadbynativespeakers.Youcanalsolistento10itEnglishwordsradiofeaturewhileyou'rewalking.
甲乙丙丁四位同学各自对AB两变量的线性相关性作试验并用回归分析方法分别求得相关系数r与残差平方和m如表 则哪位同学的试验结果体现AB两变量有更强的线性相关性
某学校为了了解该校学生对于某项运动的爱好是否与性别有关通过随机抽查110名学生得到如下2×2的列联表 由公式算得K2≈7.82 附表 参照附表以下结论正确的是
已知直三棱柱ABC﹣A1B1C1的所有顶点都在球0的表面上∠BAC=90°AA1=BC=2则•+=
曲线y=xex+2x﹣1在点0﹣1处的切线方程为.
已知mn是两条不同的直线αβ是两个不同的平面则下列命题中正确的是
若抛物线x2=ay的焦点到准线的距离为1则a=
已知fx=|3x+2| 1求fx≤1的解集 2若fx2≥a|x|恒成立求实数a的最大值.
若z=3+4i则=.
10分 TheArtofSlowReading IfyouarereadingthisarticleinprintchancesarethatyouwillonlygetthroughhalfofwhatIhavewritten.Andifyouarereadingthisonlineyoumaynotevenfinishafifth.1Theysuggestthatmanyofusnolongerhavetheconcentrationtoreadarticlesthroughtotheirconclusion. Soarewegettingstupider?Actuallyouronlinehabitsaredamagingthementalpowerweneedtoprocessandunderstandtextualinformation.Round﹣the﹣clocknewsmakesusreadfromonearticletothenextwithoutnecessarilyengagingfullywithanyofthecontent.OurreadingisfrequentlystoppedbythenoiseofthelatestemailandwearenowabsorbingshortburstsofwordsonTwitterandFacebookmoreregularlythanlongertexts.2Butwearegraduallyforgettinghowtositbackthinkcarefullyandrelateallthefactstoeachother. 3Adesperatebunchofacademicswantustotakeourtimewhilereadingandre﹣reading.Theyaskustoswitchoffourcomputerseverysooftenandrediscoverboththejoyofpersonalengagementwithprintedtextsandtheabilitytoprocessthemfully.What'stobedonethen?Mostslowreadersrealizethattotalrejectionofthewebisextremelyunrealistic.Theyfeelthatgetawayfromtechnologyforawhileistheanswer.4 PersonallyI'mnotsurewhetherIcouldevergoofflineforlong.EvenwhilewritingthisarticleIamswitchingconstantlybetweensitesskimmingtoooftenabsorbingtoolittle.Internetreadinghasbecometoorootedinmydailylifeformetochange.IreadessaysandarticlesnotinhardcopybutasPDFs.Isuspectthatmanyreadersareinasimilarposition.5YoucandownloadacomputerapplicationcalledFreedomwhichallowsyoutoreadinpeacebycuttingoffyourInternetconnection.OrifyouwanttoavoidbeingdisturbedbytheInternetyoucouldalwaysdownloadofflinereaderInstapaperforyouriPhone.Ifyou'restillreadingmyarticlethatisslowreading. A.TheInternetisprobablypartoftheproblem. B.Nowsomecampaignsareadvocatingslowreading. C.Butifyoujustoccasionallywanttoreadmoreslowlyhelpisathand. D.Thesearethetwofindingsfromtherecentresearchprojects. E.BecauseoftheInternetwehavebecomeverygoodatcollectinginformation. F.Slowreadingcanhelpconnectareadertoneighborhoodandbecomepopular. G.Someofthemhavesuggestedturningtheircomputersoffforonedayaweek.
函数fx=x2+xsinx的图象大致为
某互联网公司为了确定下季度的前期广告投入计划收集了近6个月广告投入量x单位万元和收益y单位万元的数据如表 他们分别用两种模型①y=bx+a②y=aebx分别进行拟合得到相应的回归方程并进行残差分析得到如图所示的残差图及一些统计量的值 Ⅰ根据残差图比较模型①②的拟合效果应选择哪个模型并说明理由 Ⅱ残差绝对值大于2的数据被认为是异常数据需要剔除 i剔除异常数据后求出Ⅰ中所选模型的回归方程 ⅱ若广告投入量x=18时该模型收益的预报值是多少 附对于一组数据x1y1x2y2…xnyn其回归直线=x+的斜率和截距的最小二乘估计分别为===﹣.
已知向量满足||=||=22﹣3⊥2+. 1求向量所成的角θ的大小 2若|+λ|=3求实数λ的值.
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高二下学期生物
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