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已知直线l与曲线y＝x3﹣x+1有三个不同的交点A（x1，y1），B（x2，y2），C（x3，y3），且|AB|＝AC|，则＝
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高三下学期数学《》真题及答案
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一个关系模式为YX1X2X3X4假定该关系存在如下函数依赖X1→X2X1→X3X1→X4则该关系属于
一个关系模式为YX1X2X3X4假定该关系存在函数依赖X1X2→X3X2→X4则该关系的码为____
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一个关系模式为YX1X2X3X4假定该关系存在如下函数依赖X1→X2X1→X3X3→X4则该关系属于
已知二次型 的秩为2． Ⅰ求a的值 Ⅱ求正交变换x=Qy把fx1x2x3化成标准形 Ⅲ求方程fx1
一个关系模式为YX1X2X3X4假定该关系存在如下函数依赖X1x2→X3X2→X4则该关系的码为
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一个关系模式为YX1X2X3X4假定该关系存在如下函数依赖X1←→X2X1→X3X1→X4则该关系属
已知直线ly＝ax＋1－aa∈R若存在实数a使得一条曲线与直线l有两个不同的交点且以这两个交点为端点
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若函数fx满足对于任意x1x2>0都有fx1>0fx2>0且fx1＋fx2
一个关系模式为YX1X2X3X4假定该关系存在如下函数依赖X1X2→X3X2→x4则该关系的码为__
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已知函数fx=x-a2x-bab∈Ra
有如下程序 ***主程序P．prg******子程序P1．prg*** SETTALKOFFX2
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一个关系模式为YX1X2X3X4假定该关系存在如下函数依赖X1X2→X3X2→X4则该关系属于【14
已知P1x1y1P2x2y2P3x3y3是反比例函数y=2x的图像上的三点且x1＜x2＜0＜x3则y
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如图11-3所示由相同规格的普通热轧槽钢组成的不同形式的组合截面其组合截面的惯性矩分别为Ix1Iy
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脂肪酶催化脂肪水解为甘油和脂肪酸科研人员为探究油水比例对脂肪水解度的影响[水解度＝脂肪水解量/脂肪总量×100%]做了相关实验结果如图．下列叙述错误的是
Themorningafteraneveningflightwithmythenthree﹣year﹣olddaughterIcouldn'twaittogethertoschool.Iwastiredfromtheangerandherinabilitytocommunicatebecauseofherslowedlanguagedevelopment. AsIaccompaniedherintothecarIfeltdesperate.Nothingwasrightwithourworld.ShehadbeenbornaroundthesametimethenationwaswitnessingthebirthofanotherGreatRecession经济萧条.Myjobandmyhousehadbeenvictims.Thenthishappened.Mychild'slanguagedelaywasidentifiedbutdoctorsstruggledtoproperlydiagnosisher.Ifeltlikewebothneededtoberescued. IreturnedthatafternoonasdisenchantedwiththelittlegirlIlovedaswhenIleft. Walkingslowlytowardtheschool'splaygroundgateIfoundherpreschoolteacherracingtogreetme. Youshouldhaveseenhertoday!Hisbreathywordsweresupportedbyexcitement.Ididn'tinterrupt.Seethatclimber.Hepointedtoapieceofwoodenplaygroundequipmentthatlookedlikearockwall.Inodded.WelleverydaysinceshestartedschoolShe'stiredandfailedtomakeittothetop.Hetookabreath.Andtodayshemadeit. Heexpressedhisjoyjustlikehe'dwitnessedherconquering征服MountEverestShecheeredandcelebrated!Iwishl'drecordedit..Hiswordscomfortedme.Mydaughterhadconqueredhermountain.AssherantowardmeIrecognizedsomethingIhadn'tbefore.Isawherperseverance.Isawherstrength.Isawahero. EverydaygreatnesscelebratesordinarypeoplewhodounusualthingsinbigandsmallwaysshowingcouragekindnessloveandselflessnessWeencourageyoutoclickthesebriefaccountsandinviteyoutoshareyourownstoryinourcommunity. 1Whywastheauthor'sdaughterrushedtoschool? A.Themotherwasbusywithherworkasadoctor B.Themotherhadafightwiththedaughterlastnight. C.Themotherbrokedownwhendealingwithherdaughter. D.TheyhadtosellandleavetheirhouseduetoGreatRecession. 2Whichofthefollowingbestexplainsdisenchantedunderlinedinparagraph3? A.Disturbed. B.Dissatisfied C.Distrusted D.Disappointed. 3Whatmadethelittlegirl'spreschoolteacherfeelexcited? A.ThatshesucceededinconqueringMountEverest. B.Thatshemanagedtoclimbupthewoodenclimber. C.Thatshegotthefirstplaceintheschoolsportsmeeting D.Thatshedevelopedtheabilitytocommunicatenormally. 4Whereisthetextprobablytakenfrom? A.Ontheradio. B.Fromamagazine. C.Fromaschoolpaper D.OntheInternet
某校研究性学习小组对某农业生态系统进行了调査分析并绘出了如图所示的食物网． 请据图回答 1在这个生态系统的食物网中有条食物链． 2该食物网中青蛙占有个营养级青蛙和蜘蛛的关系属于． 3请你写出蛇获得能量最多的一条食物链此食物链中蛇为初级/次级/三级/四级消费者． 4研究小组的同学对鼠这种活动能力强活动范围大的动物进行种群密度调查通常采用法． 5该生态系统的功能主要是能量流动物质循环和．其中能量沿食物链流动的特点是．
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假如你是某国际学校的学生李华你最近使用了一本XX英英词典感觉非常实用请你利用班会时间向同学们推荐它.内容要点如下 1.特色如词汇量用法例句等方面 2.使用心得. 注意1.词数100左右 2.可以适当增加细节以使行文连贯 3.开头和结尾已经给出不计入总词数. Helloeveryone!
Ourmindisapowerfulthingwhichcaneitherimproveorruinourmood.Manyofushaveproblemswithnegativethoughtsplayingonthechannelofourmindsbutifyou'reengaginginitconstantlyandyoubelieveititcouldbedestroyingyoursenseofself﹣esteem.1 Whatcanyoudo?Herearesomesuggestions 1.Liveinthemoment Self﹣talkissosubtlethatweoftendon'tnoticeitseffectonourmoodandbeliefsystems.Keythingstonoticeareifonlyorwhatifstatementstheformerkeepyoustuckinthepastwithregretwhilethelatterkeepyoufearfulofthefuture.2Sostayinthepresentmoment. 2.Visualizethegoodthings Ifwewanttochangethenegativetapesplayinginourheadswehavetovisualizeourselvespositively﹣thatmeansseeingyourselfnon﹣judgmentally.Howwouldthatlook? Drawapictureinyourmindandexpandonit. 3.3 Whateveryoubelieveyou'llexperiencemoreandyou'llalsofindyourselfbehavinginwaysbelievethatareinyourbeliefs.Sostartbelievingthebestaboutyourselfactasifyoubelievethatyou'reavaluableandworthyperson. 4.Developpositivethoughts 4Whatareyourstrengths?Whatareyougoodat?Keepyourthoughtsinthehere﹣and﹣now.InsteadofsayingI'mnotgoodenoughtrysayingIamcapable.IacceptmyselfthewayIam. Thinkingpoorlyaboutourselvesgetsusnowhereandisextremelyself﹣limiting.5 A.Payattentiontothecauses B.Recognizethatactionsalwaysfollowbeliefs C.Thereisnothingyoucandoaboutthepastandthefutureisn'thereyet. D.Inshortitbringsyourfocusonyourfailuresandthatgetsyounowhere. E.Negativethoughtsaccountforbadfeelingsthathookyouintobelievingthatyou'reafailure. F.Insteadofalwaysputtingyourselfdownthinkofsomethingsyouactuallylikeaboutyourself. G.Decidetodaytoturnoffthenegativeself﹣talkchannelinyourmindanddevelopyourtruepotential.
Cassielivedalonelylife.Shewouldwanderthroughtheforesteating1fallfruitswhileotherbirdsflewamongthetrees. Whycannotyoufly?theywouldask.Yourweaklittle2wingcannotevenliftyouofftheground!theywouldteaseher.You're3shametobirdstheywouldoffendher. Cassiewasfeelingincreasinglyfrustratedand4usesoshemadeuphermindtoleavetheforestforgood.Justasshewalkedfreefromtreessheheardadeepvoice5callfrombehind.Cassieturnedaround.6wasalargetreethatsignaledtohertocomebackintotheforestWeneedyoubadlyheresaidthetree.Werelyonyou7eatourfruitsandspreadourseeds.Theotherbirdsmaythinkyouareworthlessbutyouareactually8muchusefulbirdintheforest.Pleasedon'tgoyouareirreplaceable.Cassicbeamedforthefirsttimeinmanyweeksand9returntotheforest.Thefruitshadnevertastedsogood. It'seasytocompareyourskillstotheabilitiesofothersandfeelinadequate.It'seasytolistentothenegativevoicesofothersandbelievethem.Butbear10mindthatyouareessentialyouareremarkableandyouareirreplaceable!
Reutersreportedthatthescientist'seffortsgotrewardedwhenthetwinchickenswereclonedinthelabafteryearsofexperiments.Thisbreakthrough1possibleenabledpeopletobringtheiradoredpetsbacktolife.2itbotheredhimfromtimetotimethattheirhealthwasinpoorconditionbecausetheywere3abletoresistillnesses.Thisdrawback4casthimdown.Merelytwoweekslatertheclonesandtheircarrierdied5struckfrustrationintohisheart.Heretiredbeforeheattainedhisambitionandbecameamemberofanoperachorustorelievehisdepression. Shortlyafterwardsthemediapublishedaconservative6argueobjectingtocloningowingtomoralproblemsandsuggestedcommercialprofitsfromcloning7forbid. When8interviewthescientiststaredatthedecorationsontheceilingthinkingforawhileandthensaidI'mnotinfavour9anyarbitraryassumptionbut10undertakecloningdoesdifferfromthestraightforwardprocedureofmakingloafsoutofflour.Untilweaccumulateenoughexactknowledgeanypracticeisinvainandisboundtofail.
某课题组为了研究赤霉素GA3和生长素IAA对植物生长的影响切取菟丝子茎顶端2.5cm长的部分茎芽置于培养液中无菌培养．实验分为AB两组分别培养至第18天再用适宜浓度的激素处理30天测量茎芽长度结果如图甲．另一小组将洋葱根尖分生区细胞用不同浓度的生长素处理若测得经某一浓度的生长素处理前后的细胞内DNARNA蛋白质含量相对值的变化如图乙所示．下列说法正确的是
Exercisecouldnotonlybenefityourbodybutalsoimproveyourmemoryresearchersfound1recent. IntheirpaperresearchersintheUnitedStatesandJapan2introducetheirexperimentandconclusion. Scientistsinvited36volunteers3wereintheirearly20stodo10minutesoflightexercisebeforetakingamemorytestinwhichthey4showpictureslikebroccoli西兰花orpicnicbasketsandaskedtorecallthemlater.Thesameexperimentwasrepeatedwiththesamegroupofvolunteerswithoutexercising.Thememorytaskreallywasquite5challengesaidMichaelYassaco﹣authorofthestudy.Weusedverysimilaritemstoseeiftheywouldremember6itwasthisexactpicnicbasketversusthatpicnicbasket. Researchersalsoscannedbrainsofsomeoftheparticipantsduringtheexperiment. Theyfoundincreasedcommunicationbetweenparts7involveinthestorageandrecollectionofmemoriesinbrainsofthosewhohadexercised. Thissuggestedthatjust10minutesoflightexercisemighthaveapositiveeffect8memorypower. Asall9volunteersintheexperimentwererelativelyyoungresearchersarestillworking10lookattheinfluenceoflightexerciseonolderpeople.OurmaingoalistotrytodevelopanexercisewaythatcanbeusedbyolderadultswhomighthavedisabilitiessaidYassa.
某DNA上的W基因发生突变导致合成的mRNA上一个碱基C变成A．下列叙述错误的是
新一代基因编辑CRISPR/Cas9术的实质是用特殊的引导序列sgRNA将Cas9酶﹣“基因剪刀”精准定位到所需切割的基因上然后进行编辑．科研人员设想利用新一代基因编辑技术来预防艾滋病．回答下列问题 1动物细胞中没有编码Cas9酶的基因可通过构建用法将其导入受体细胞最终表达出Cas9酶． 2CCR5蛋白是HIV病毒入侵机体细胞的主要辅助受体之一HIV通过识别膜通道蛋白CCR5侵入宿主细胞．为有效阻止HIV侵染新分化生成的T淋巴细胞科研人员将sgRNA序列导入骨髓细胞中以构建sgRNA﹣Cas9酶复合体．Cas9酶可以催化键断裂以实现对DNA序列的定向切割．设计sgRNA序列需要根据的核苷酸序列原因是． 3为检测T淋巴细胞的CCR5基因是否成功被编辑采用技术检测是否含有CCR5基因还需要对蛋白进行检测．
下列关于细胞及其产生的物质的叙述正确的是
神经元的离子通道是跨越磷脂双分子层的蛋白质对特定刺激发生反应时才瞬时开放促使特定离子顺浓度梯度运输如图所示．下列相关叙述错误的是
大肠杆菌可以直接利用葡萄糖也可以通过合成β﹣半乳糖苷酶的乳糖分解为葡萄糖和半乳糖加以利用．将大肠杆菌培养在含葡萄糖和乳糖的培养基中．测定其细胞总数及细胞内β﹣半乳糖苷酶的活性变化．据图分析下列叙述合理的是
已知某植物花色性状受三对独立遗传的等位基因控制同时存在三种显性基因时开大红花只存在两种显性基因时开红花只存在一种显性基因时开粉红花不存在显性基因时开白花．回答下列问题 1纯合大红花与白花的品种杂交获得F1F1自交F2的表现型及比例为F2中开粉红花的基因型有种红花中纯合子所占的比例为． 2从F2中选出甲乙两株粉红花植株请通过一代杂交实验判断甲乙两植株是否一含有同种显性基因．要求写出杂交方案预期结果及结论
WWP2基因在肿瘤细胞中高度表达WWP2蛋白参与肿瘤细胞的生长存活和转移等．为获得较多WWP2蛋白利用基因工程技术设计引物其中正向引物5′含有EcoRI酶切位点反向引物5′含有XhoI酶切位点．将WWP2基因与相应载体构建重组质粒导入人胚肾细胞．回答下列问题 1利用上述的引物以肺癌细胞的cDNA为模板通过扩增的编码序列获得需要的目的基因片段． 2把获得的目的基因片段和相应载体都用进行酶切分别在5′端与3′端形成避免自身环化．然后利用将目的基因片段和相应载体连接得到重组质粒． 3先将重组质粒导入经处理过的大肠杆菌细胞培养后从中分离得到较多的重组质粒． 4培养人胚肾细胞时先用使人胚肾细胞分散成单个细胞用含有的合成培养液培养并将培养瓶置于体积分数为5%的与空气混合气体的培养箱中培养． 5将重组质粒导入人胚肾细胞中48小时后提取蛋白质并检测到WWP2蛋白说明． 6致癌因子会损伤肺泡细胞中的使原癌基因和抑癌基因发生突变．研究WWP2蛋白的表达为肺癌治疗新靶点奠定了基础．
阅读下面短文根据所给情节进行续写使之构成一个完整的故事. WhenIwastenyearsoldIlivedwithmyfamilyinasmallhouseinruralSouthJersey.IoftenaccompaniedmymothertotheA&Ptobuygroceries.WithoutacarwewalkedandIwouldhelphercarrythebags. Mymotherhadtoshopeverycarefullyasshewasawaitressandhersalarybarelysustained勉强维持us.OnedaywhileshewasweighingpricesapromotionaldisplayfortheWorldBookEncyclopediacaughtmyeye.Thevolumeswerebeautifullycream﹣colored.VolumeIwasninety﹣ninecentswithaten﹣dollarpurchase. AllIcouldthinkofwhileshoppingwasthebook.Istoodattheregister收银台withmymotherholdingmybreathasthecashierranguptheitems.Itcametooverelevendollars.Mymotherproducedafivesomesinglesandahandfulofchange.AsshewascountingoutthemoneyIsomehowfoundthecouragetoaskfortheencyclopedia百科全书.Couldwegetone?Isaidshowingherthedisplay.It'sonlyninety﹣ninecents. Ididnotunderstandmymother'sincreasinganxietyshedidnothaveenoughchangeandhadtosacrificealargecanofpeastopaytheamount.NotnowPatriciashesaidsternly.Todayisnotagoodday.Ipackedthegroceriesandfollowedherhomeupset. ThenextSaturdaymymothergavemeadollarandsentmetotheA&Palone.Twoquartsofmilkandaloafofbread﹣﹣﹣that'swhatadollarin1957.IwentstraighttotheWorldBookdisplay.TherewasonlyonefirstvolumeleftwhichIplacedinmycart购物车.Ididn'tneedacartbuttookonesoIcouldreadasIwentupanddowntheaisles.AlotoftimewentbyandIknewIhadtoleavebutIcouldn'tbeartopartwiththebook.WithnodetectiveinsightIimpulsively冲动地putitinsidemyshirtandzippedupmyjacket.IwasatallskinnykidandIamcertaintheshapeofthebookwasobvious. Paragraph1MyheartbeatingrapidlyIheadedfortheregister. Paragraph2Backhome.ItoldmymotherwhatIhadpromisedthedetective.
PrepareYourselfforaBetterTOEFLScore TheTOEFListhemostwidelyusedlameassessmentexamforAmericancollegesoruniversities.ManyforeignstudentsworryabouttakingtheTOEFLbecauseitisessentialtomeettheirgoals.1Butalowtestscorewilllimittheirchoicesforfinancialaidandadmissiontotopschools.SohowtoprepareyourselfforabetterTOEFLscore? Whatwillyoufocuson? PlanwhenyouwilltaketheTOEFL.Ifpossibleregistertotakethetestevenifthedateisseveralmonthsfromnow.Thiswillgiveyouagoodreasontostudy.Takeasampletestonlineorfromatestpreparationbooktofindoutwhereyouneedtoimprovethemost.2Thiswillhelpyoutoplanyourstudiestodeveloptheskillsyouneedtogetabetterscore. 3 TheEducationalTestingServicewebsitehasafreeonlinecoursetohelpyoupreparefortheTOEFL.Therearealsosamplepreparationquestions.ApartfromansweringthosequestionstrytosurroundyourselfwithEnglish.ListentostoriesonVOA'sLearningEnglishwebsite.WatchmovieswhereEnglishisspoken.ReadEnglish﹣languagenewspaperstokeepupwithnewwordsthatrelatetocurrenteventsandtechnology. Whenwillyoustudy? 4Butifyourpracticetestscoreismorethan20pointsbelowyourgoalyoumayneedtoimproveyouroverallEnglishabilityandthatmaytakeyears.Togetagoodscoreyouneedtosetasidetimetostudysetgoalsandmeasureyourprogress. TherealgoalofthetestistomeasurehowwellastudentcancommunicateinanEnglish﹣speakingclassroom.5 A.Howwillyoustudy? B.Donotdependoninformaladviceortricks. C.Goodmarksonthetestwillopenmanydoors. D.Doyoudowellinreadingbutnotsowellinlistening? E.Exportssaythatyoushouldstudyforatleasttwomonthsbeforetakingthetest. F.ExposeyourselftoEnglishonadailybasisandimprovementissuretofollow G.ATOEFLscoremaybenecessarytogetastudentvisatoanEnglish﹣speakingcountry.
阅读下面短文根据其内容写一篇60词左右的内容概要. Paperlessofficewasfirstcoinedin1975.Fourdecadeslaterwe'restillchasingthepaperlessofficedream.Takethefinancialindustryforexample﹣itisoneoftheslowerindustriestohugdigitaltransformation.Manyfinancialinstitutionstodaystillsendouttradeconformationsbymail.Icantellyoufromfirsthandexperiencethatgoingpaperlessisbynomeansimpossible.TheCentricDigitalofficeisapaperlessworkenvironmentwherealltheofficeoperationsgodigitalwhichhasamazedourbusinesspartners. Actuallycompaniesneedtostressthebenefitsofadigitalcultureforcommunications.Goingpaperlesscansavetimeandmoney.Youcouldsaygoodbyetocostlyrepairsofficesupplyorderswastedemployeetimeandsoon.Besidesforbiddingpaperintheofficeforcesinformationtobe100%digitalwhereyoucanmakeendlessamountsofbackups备份whicheasilyincreasetransparency透明.Nottomentiontoptalentswanttoworkfordigitalcompanies. Youmightthinkthesecrettoapaperlesscompanyispurelytechnology.Wellnotreally.ThankstoproductslikeiPadssmartphonesandcloudservicestheabilitytogopaperlessishighlyaccessible.Yetevenwithallthistechnologycompaniescontinuetorelyonpaper.It'snotbecausetheydon'thaveaccesstothetechnologybutbecausethey'relackingthepoliticsorganizationalstructureandstrongdesiretochange.Inordertogopaperlesscompaniesneedtochangethewaytheythinkandoperate.Thedecisionneedstobemadeandcriedoutandeveryoneneedstoworktogethertomakeit. Yesthepaperlessofficehasbeenaverylongtimeinthemaking一butitnolongerhastobe.Withnumerousamountsofsoftwareservicesappsandtechnologyavailabletodaytheonlythingweneedtodoistomakethedecisiontogopaperlessandseeitthrough.
Forsomepeoplewalkingorrunningoutdoorsisaeatwaytoworkout.Whatmaynotbesopleasantisseeingtrashallovertheground.Wellsomepeoplearedoingsomethingaboutit.Theyareplogging! PloggingbeganinSweden.ThenamecombinetheSwedishwordplockawhichmeanstopickupandthewordjoggingwhichmeanstorunslowly.ASwedishmannamedErikstartedthemovementin2016.OntheWorldEnvironmentDaywebsiteEriksaysthathemovedtoStockholmfromasmallcommunityinnorthernSweden.Eachdayhewouldridehisbiketowork.Concernedabouttheamountoftrashandlitterhesaweachdayonhiswaytoworkhetookmattersintohisownhands. PloggingbythattermmayhaveofficiallybeguninSweden.Butmanypeoplewhoexerciseoutdoorshavebeendoingthisforyears.TakeJeffHorowitzforexample.HeisapersonaltrainerinWashingtonD.C.Heoftenpicksuptrashwhilerunningoutside.Heevenasturneditintoagamehewilltrytopickupthetrashwithoutstopping.Ididn'tknowitwasathingreally.Thisisjustmypersonalethics道德标准whereIgoforarunandifIhappentoseeapieceofgarbagelyingaroundandit'swithinreach﹣﹣﹣itisakindofalittletestformetoseeifIcangrabitandthrowitinanearrashcanwithoutstopping.AndthatwayIthinkitgivesmealittleexerciseandalittlefocusformyrun.Andithelpscleanuptheneighborhoodheannounced. Todayloggingisanofficialactivityonethatisbecomingincreasinglypopular.Citiesaroundtheworldnowholdloggingevents.Iwouldjusthopepeoplewouldthinktwicebeforedroppingagarbageontheround.Wehavecontainers…seemsoneveryblock.Soit'seasytoputyourgarbageinthetrashcans.Ijustthinkpeopleshouldthinkaboutitalittlebitmore.Idohopeonedaytherewillnotbeaneedforlogging.saidaninterviewee. 1Whichofthefollowingcanreplacetheunderlinedphrasetookmattersintohisownhands? A.calledonpeopletojoinhim B.appealedtopeopletogogreen. C.begantopickupthetrash. D.hadthecollectedtrashrecycled. 2LikeJeffHorowitzloggingtomanypeoplehasbecomeaanact. A.automatic. B.irresistible. C.arbitrary D.temporary 3WhatistheideathatLoggingeventsaremeanttopromote? A.loggingistrulybeneficial B.Trashcansshouldbewithinreach C.Litteringisnotacceptable. D.Communitiesshouldbekeptclean. 4Whatcanbeasuitabletitleforthepassage? A.NewExerciseEnjoysunbelievablepopularity B.NewExerciseTrendAlsoHelpsEnvironment C.Plogging﹣aFashionableWaytoclearwaste D.Plogging﹣anExerciseOriginatinginSweden
某生物兴趣小组希望通过遗传学杂交实验探究一些遗传学问题他们获得了稳定遗传的高茎黄粒品系1和矮茎白粒品系2两种玉米高茎A对矮茎a为显性白粒B对黄粒b为显性已知两对基因均位于常染色体上不考虑交叉互换． 1探究的问题 控制这两对相对性状的基因是否位于一对同源染色体上． 2请设计一组最简单的实验方案探究上述遗传学问题 ①观察和统计F1的性状及比例保留部分F1种子． ②观察和统计F2的性状及比例． 3实验分析 ①如果F2中表现型与比例为则控制这两对相对性状的基因不位于一对同源染色体上． ②如果F2中表现型与比例为则控制这两对相对性状的基因位于一对同源染色体上且基因连锁．
实施乡村振兴战略是建设美丽中国的关键我国是世界第一的鹅养殖大国约占世界出栏量的90%快速识别刚孵化的雏鹅性别对规模化养殖至关重要．某白鹅品种甲刚孵化出来的维鹅绒羽通常呈黄色或浅褐色饲养9个月后雏鹅性成熟绒羽退尽换上新羽羽色都是白色．科学家在繁育过程中选择成年10月龄公鹅40只母鹅200只进行混群饲养随机交配孵化获得1个批次的雏鹅G1观察雏鹅的绒羽和性别统计结果如下．请回答 1同一只鹅的雏鹅的绒羽羽色与成体的羽色有很大差异这说明控制羽色的基因羽毛的差异是基因选择性表达的结果． 2据表推测白鹅品种甲的雏鹅绒羽颜色为显性性状推测绒羽颜色遗传最可能是伴性遗传的理由是． 3为进一步确定白鹅品种甲的绒羽颜色的遗传方式从该批次白鹅G1中选取雏期绒羽颜色为的公鹅和的母鹅进行杂交实验通过子一代F1的绒羽色和性别进行确认若F1中则说明控制绒羽色的基因只在Z染色体上且能快速分辨雏鹅性别． 4若以上分析正确第1批次G1的母鹅中浅褐色绒羽的基因频率是推算依据是．
我国科技人员创造了浮床生态工艺法净化生活污水含有机物和无机物在水域中固定浮床上种植特殊的水生半水生植物以吸收水中的氮磷等元素．回答下列问题 1流经该水域生态系统的总能量是． 2生活污水流入水域中通过物理沉降化学分解和使污水得到净化．若流入该水域的生活污水过量则会导致生态系统遭到破坏原因是． 3浮床生态工艺法还能抑制藻类的繁殖防止“水华”发生原因是．答两点即可
Greenlifestyleisbecomingincreasinglypopularnowadays.1Youdon'thavetocompletelychangethewayyouliveyoujustneedtomakeafewsmallchanges.Fromrecyclingtogreenshoppingeachsmallchangeyoumakecanreallymakeadifference.Herearesomebenefitsoflivingagreenlifestyle. Helptheenvironment.Bybeingenergy﹣efficientandusinggreenproductsyoucanreduceyourinfluenceontheenvironment.Youcanhelppreserveournaturalresourcesandreducepollution.2.Itdoesfeelveryrewardingwhenyoustartmakingpositivechangesandfeelingasthoughyou'remakingadifferencetosuchanimportantcause. Liveahealthierlife.Ifmorepeoplecommittobeinggreenthenwe'llbeabletoliveinahealthierenvironmentwithlesspollutionandbetterairquality.You'realsomorelikelytomakebetterchoiceswhenitcomestofoodandyoucouldfindyourselfleadingamoreactivelifestyle.Growingyourownvegetablesisaveryhealthywaytoliveaswellasbuyinggreennaturalfoods.Cyclingandwalkingtoplacesinsteadofusingyourcarcanhaveabiginfluence.3. Savemoneyonbills.Youcangreatlyreduceyourenergybillsbyusingenergyefficientequipment.4Recyclingisalsoanothergreatwayofsavingmoneyandhelpingtheenvironment. 5.Onceyouhavepickedupsomegoodtipsandgreenlivingtechniquesyoucanpassthemontootherpeople.Youcanalsotalktofriendsandfamilyandinformthemofthebenefitsofgoinggreen.Yourchildrenwillgrowupunderstandingtheimportanceoflivingagreenlifestyleandwilllearnhowtoreducetheirinfluenceontheenvironment. A.Educateothers. B.Meetlike﹣mindedpeople. C.Itwillalsomakeyoumuchfitter. D.Therearelotsofwaysofsavingmoney. E.Youcanalsodoyourpartforwildlifeconservation. F.Livingagreenlifestyleisn'tashardasitmightseem. G.Ifyougrowyourownproduceyouneedn'tspendasmuchonfood.
为了研究水生生物对富营养化水体中磷的去除作用研究人员从某城市内河中取水样分别设置水葫芦鲢鱼“水葫芦+鲢鱼”等不同处理组进行实验分别取样检测水体中总磷浓度变化结果如图．下列相关叙述错误的是
下列有关生物学实验操作正确的有 ①探究温度对酶活性的影响可选择过氧化氢溶液作底物 ②在电子显微镜下拍摄到的叶绿体的结构照片属于物理模型 ③在花生子叶薄片上滴加苏丹III染液发现满视野都呈现橘黄色于是滴1﹣2滴50%酒精洗去浮色 ④在模拟细胞大小与物质运输的关系时琼脂块表面积和体积之比是自变量氢氧化钠扩散速度是因变量 ⑤用无水乙醇对绿叶中的色素进行提取和分离溶解度越大的色素在滤纸条上扩散速度越快 ⑥在观察细胞内DNA和RNA分布的实验中可使用酒精来改变细胞膜通透性加速染色剂进入细胞．
7.5分Peopletendtoacceptgroup'sstandardsofbehaviorandthinkinginagroupwork.Manyillustrations例证couldbegivenofthisfromeverydaylifebutwhatisofparticularinteresttopsychologistsishowmuchpeople'sjudgmentsandopinionscanbechangedasaresultofgrouppressure.Aschandothersnoticedthatpeopleinagroupwillagreetostatementsthatarecontrarytotheevidenceoftheirsenses.Itwouldbeamistaketothinkthatonlyparticularchangeablepeoplearechosentotakepartinexperimentsofthistype.Usuallyhighlyintelligentandindependentpeopleareused. Inatypicalexperimentthisiswhatmayhappen.Theexperimenterasksforvolunteerstojoinagroupwhichisinvestigatingvisualsense.Theparticipantsarenotthereforeawareoftherealpurposeoftheexperiment.Eachvolunteeristakentoaroomwherehefindsagroupofaboutsevenpeoplewhoarecooperatingwiththeexperimenter.Thegroupisshownastandardcardwhichcontainsasingleline.Theyarethenaskedtolookatasecondcard.Thishasthreelinesonit.Oneisobviouslylongerthanthelineonthefirstcardoneisshorterandonethesamelength.Theyhavetosaywhichlineonthesecondcardisthesamelengthasthelineonthestandardcard.Theothermembersofthegroupanswerfirstbuttwhatthevolunteerdoesnotknowisthattheyhavebeentoldtopickoneofthewronglines.Whenhis turncomesheisfacedwiththeconsistentopinionoftherestofthegroup﹣alltheothershavechosenlineAbuthequiteclearlyseeslineBascorrect. Whatwillhedo?AccordingtoAschmorethanhalfofthevictimschosenwillchangetheiropinion.Whatisequallysurprisingisthatwheninterviewedabouttheiranswersmostexplainedthattheyknowthegroupchoicewasincorrectbutthattheyyieldtothepressureofthegroupbecausetheythoughttheymustbesufferingfromanopticalillusion视觉假象orbecausetheywereafraidofbeingdifferent. 1Thepsychologistsareespeciallyinterestedin. A.theevidenceoftheexperiment B.thechangesintheattitudesofpeople C.thedifferenceinpeople'sbehavior D.thedegreeofchangesofpeople'sopinions 2Whymorethanhalfofthevictimschangestheiropinionsintheexperiment? A.Becausetheyhadbeentoldabouttheanswer. B.Becausethoughtthegroupchoicewascorrect. C.Becausetheysubmittedtothegrouppressure. D.Becausetheireyesweresufferingfromillusion. 3Thepurposeoftheauthorinwritingthispassageisto. A.illustratetheinfluenceofgrouppressureonindividuals B.encouragepeopletoactagainstanygroup'sopinion C.invitemorevolunteerstojoininAsch'sexperiment D.tellthereadershowtoperformpsychologicalexperiment
胰腺是哺乳动物重要器官科学家用胰腺进行科学实验探究其重要功能．请回答 1斯他林和贝利斯剪取狗小肠并刮下黏膜将黏膜与稀盐酸混合加砂子磨碎制成提取液发现提取液可促进胰腺分泌胰液．该实验验证的假设是． 2胰腺中大部分是胰腺细胞其间散布着胰岛胰岛A细胞和胰岛B细胞分布其中其分布方式为填“胰岛A细胞胰岛B细胞分别集群形成胰岛”/“胰岛A细胞胰岛B细胞及其他细胞混合集群形成胰岛”． 3胰腺中分泌的胰高血糖素与肝细胞膜上的受体结合后调节糖代谢过程这反映了细胞膜具有的功能．人体内需要胰腺源源不断地分泌胰岛素以维持激素含量动态平衡的原因是． 4科学家在豚鼠胰腺腺泡细胞中注射3H标记的亮氨酸并破坏了腺泡细胞中全部的高尔基体检测放射性的聚集和转移情况．结果发现放射性只在细胞内进行转移但却未出现在细胞外这表明．
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