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如图是某草原生态系统中部分生物之间关系的示意图，请根据图回答下列问题． （1）图中鼠和食草昆虫属于第 营养级． （2）该生态系统中，许多食物链彼此交错连接成 ． （3）图中最长的食...
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高三上学期生物《》真题及答案
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下图是某草原生态系统中部分生物之间关系的示意图请根据图回答下列问题1生态系统中的生物成分包括生产者消
右图是某草原生态系统中部分生物的食物关系图请据图回答狼每增加l千克体重至少消耗绿色植物千克
4分2013•连云港图是某草原生态系统中部分生物之间关系的示意图据图回答下列问题l该草原生态系统中除
下图表示温带草原生态系统中部分生物构成的食物网如果人类大量捕杀鹰草原生态系统将受到严重破坏这说明
生态系统无调节能力
生态系统的调节能力是无限的
只有绝对禁捕野生动物，生态系统才有调节能力
生态系统调节能力是有限的
图4是某草原生态系统中部分生物之间关系的示意图据图回答下列问题l该草原生态系统中除了图示的生物成分外
图一是某温带草原生态系统中部分生物之间关系示意图图二是鸟卵结构示意图据图回答1该草原生态系统中除了图
右图是某草原生态系统中部分生物的食物关系图请据图回答从生态系统的成分看狼属于
图一是某温带草原生态系统中部分生物之间关系示意图图二是鸟卵结构示意图据图回答1该草原生态系统中除了图
下面图甲表示某草原生态系统的能量流动示意图图乙表示该生态系统狼和兔的数量波动情况请据图分析回答下列问
右图是某草原生态系统中的部分食物关系图请据图回答下列问题该生态系统中含能量最多的生物是生态系统能量流
下图是某草原生态系统中部分生物之间关系的示意图请据图回答问题1生态系统中的生物成分包括生产者消费者分
右图是某草原生态系统中部分生物的食物关系图请据图回答猫头鹰和蛇是关系
如图是某草原生态系统中部分生物之间关系的示意图请据图回答1该草原生态系统中除了图示的生物成分外还应具
右图是某草原生态系统中部分生物的食物关系图请据图回答该生态系统能量的最终来源是
下面图甲表示某草原生态系统的能量流动示意图图乙表示该生态系统狼和兔的数量波动情况请据图分析回答下列问
图6和图7分别是某生态系统中的碳循环示意图和草原生态系统的能量流动示意图请据图回答下列问题一根据图6
下图是某草原生态系统中部分生物之间关系的示意图请据图回答问题1生态系统中的生物成分包括生产者消费者分
2013•连云港图是某草原生态系统中部分生物之间关系的示意图据图回答下列问题l该草原生态系统中除了图
如图是草原生态系统的食物网示意图请据图回答1该食物网有__________条食物链最长的一条是___
右图是某草原生态系统中部分生物的食物关系图请据图回答图中是共有条食物链
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IhavebeenlearningEnglishforthelastfiveyearsandoneofthethings1hashelpedmetoimproveisreading.Ilovereadingandoftenreadduringmyfreetime.FirstI2startreadingeasythingsinEnglishlikerecipes食谱forcookingandshortstories3writeespeciallyforlanguagelearners.ThenImovedontolongerstoriesandnewspaperarticles.4firstIfoundthatreadingwasdifficultbecauseofthevarietyofvocabularyandthegrammar5thissoonbecameeasierandIfoundthatIcouldunderstandmoreandmoreof6Iwasreading.Ididn'tworryifIdidn'tknowallthewordsasIcouldstillunderstandthemainideas.ReadinghashelpedimprovemyEnglishinmanyways.I'mnotonly7betterandquickerreaderbutalsomy8spellwritinggrammarandvocabularyareallmuchbetter.IthinkIhaveimprovedfaster9someofmyfriendswhohavebeenlearningatthesametimeasme.SoIwouldsaythateveryonewhowantstolearnalanguage10quickshouldread.
阅读下面短文根据其内容写一篇60词左右的内容概要. Whatiseco﹣fashion?Eco﹣fashionisaboutmakingclothesthatconsiderstheenvironmentthehealthofconsumersandtheworkingconditionsofpeopleinthefashionindustry. Acloserlookatthefashionindustrypointsoutmanyproblemsthatarecommonpracticesinthecreationofourfashionsfromthefieldtothefactory.Firstlytheproductionoftextilespollutestheenvironmentheavily.Cotton﹣plantingusespesticidessheep﹣farmingandwool﹣cleaningbringaboutglobalwarming.Secondlyeverystageofclothingproductionconsumesagreatdealofenergyandsomealsoinvolvechemicalswhichobviouslydoharmtothesurroundings.Inadditionthereisalotofwasteproducedintheprocessespeciallyintheformofpollutedwater.Thirdlygrowingpurchasingpowerandourshoppinghabitsfurtherworsenthebadeffects.Wearenowbuyingclothesinincreasingquantitiesandwearealsoquicktothrowawayclothesthathavebeenwornonlyacoupleoftimes. Thenhowtosolvetheproblem?Toalargedegreeitisthefashionproducersthatreallyhavethepowerandtheresponsibilitytoshapeourfuture.Thereareagreatmanywaystheseproducerscanreducetheirecologicalfootprintfromswitchingtogreenenergyandreducingenergyusethroughselectingsustainablematerialsandchoosinglocalsupplierstorecyclingandminimizingwaste.Ontheotherhandasconsumerswecanallplayourpartbyselectingenvironmentallyfriendlyclothingandreducingclothingbuying. Thereissomeconcernthateco﹣friendlyfashionsarejustatrendthatwewilleventuallygrowtiredofbutwecanmakesurethatdoesn'thappen.Nowmanypeoplearebeginningtoshopfororganicfoodproductsbecausethebenefitsofeatingfoodfreeofchemicalsareimmediate.Theyrelatedirectlytoourpersonalhealth.Infactchoosingeco﹣fashioncanalsodogoodtoourpersonalhealththoughitismostlydonebywayofkeepingthehealthoftheplanet.
已知函数与gx＝2elnx+mx的图象有4个不同的交点则实数m的取值范围是
下列与真核生物细胞核有关的叙述错误的是
某工厂的某种产品成箱包装每箱200件每一箱产品在交付用户之前要对产品作检验如检验出不合格品则更换为合格品．检验时先从这箱产品中任取20件作检验再根据检验结果决定是否对余下的所有产品作检验．设每件产品为不合格品的概率都为p0＜p＜1且各件产品是否为不合格品相互独立． 1记20件产品中恰有2件不合格品的概率为fp求fp的最大值点p0． 2现对一箱产品检验了20件结果恰有2件不合格品以1中确定的p0作为p的值．已知每件产品的检验费用为2元若有不合格品进入用户手中则工厂要对每件不合格品支付25元的赔偿费用． i若不对该箱余下的产品作检验这一箱产品的检验费用与赔偿费用的和记为X求EX ⅱ以检验费用与赔偿费用和的期望值为决策依据是否该对这箱余下的所有产品作检验
假设在特定环境中某种动物基因型为BB和Bb的受精卵均可发育成个体基因型为bb的受精卵全部死亡．现有基因型均为Bb的该动物1000对每对含有1个父本和1个母本在这种环境中若每对亲本只形成一个受精卵则理论上该群体的子一代中BBBbbb个体的数目依次为
对于函数有下列4个结论 ①任x1x2∈[0+∞都有|fx1﹣fx2|≤2恒成立 ②fx＝2kfx+2kk∈N*对于一切x∈[0+∞恒成立 ③函数y＝fx﹣lnx﹣1有3个零点 ④对任意x＞0不等式恒成立则实数是的取值范围是． 则其中所有正确结论的序号是．
与他争论是没用的因为他非常固执.argue .
OdysseusisaliteraryfigureintheOdysseywrittenbyHomer.He1rejectthecomfortablelifeofaGreekkingandmadeapromisetohelpanotherGreekleaderMenelaus.Butthewardraggedonandonandhewasaway2hisfamilyfortenyears.Duringthistimethefortunesofthewarweresochangeablethatnoonecouldpredict3wouldwin. OdysseusbecametiredofthewarandthedelayinTroy.He4urgentwantedtoreturnhomesowhentheGreekkingshadtheirregular5weekmeetinghesuggestedthattheytakeanopportunity6tricktheTrojans. TheGreeksbuiltagiantwoodenhorsesothatmencouldhideinsideit.TheGreeksthenpretendedtoleaveaboardtheir7shipasiftheywerediscouragedbythe8longofthewar.TheTrojansblessedtheirGodfortheirgoodfortuneandpreparedtocelebrate.ThatnightthemenclimbedoutofthehorseandopenedthecitygatestotheGreekarmy.TheTrojansheardthesoundofthewarningbell9announceaGreekvictory.Thewarended10thepunishmentoftheTrojanpeoplewasonlyjustbeginning.
SanFranciscoknownasTheCitybytheBaypacksalotoffun. ViewofGoldenGateBridgefromBakerBeach AsoneofthemostfamoussightsinallofSanFranciscotheGoldenGateBridgeisanabsolutemust﹣see…ThereareafewgoodspotstoviewitfrombutmypersonalfavoriteisBakerBeach.Thisisalsoaparticularlygoodspottobuyamealfromalocalmarketlaydownablanketandenjoyapicnicintheviewofthefamousbridge. VisittheMuseeMecanique Fisherman'sWharf码头isoneofthemosttouristyareasofSanFranciscoandtheoverpricedcrowdedsightscanbetiring.ButonWharf41there'sauniqueattractiontheMuseeMechanique.Thismuseumhasoneofthelargestcollectionsofoldindoorsgamemachinesintheworldwhichoffersgraetamusements.Entryisfreeandit'sonlyacoupleofquarterstoplaythegames. EatatSparkSocialFoodTrucks Withsuchavariouspopulationitcanbedifficulttodecidewhatcuisinetoenjoyfordinner.LuckilyatSparkSocialFoodTrucksintheMissionBayyoucantryalittlebitofeverything!Notonlyisthefooddeliciousbutthefoodtruckhasacommunityfeelwithweeklyeventsandfreedesserts. HaveTeaattheJapaneseTeaGarden IfyoudesireforsomecalmonthesomewhatnoisystreetsofSanFranciscotheJapaneseTeaGardenisperfect.LocatedinGoldenGateParkthegardenlooksexactlylikeJapan.Andyoucanenjoyteainthetraditionalteahouseoverlookingalake. 1WhatdoestheMuseeMechaniqueoffer? A.Amusements. B.Picnicspot. C.Peace. D.Deliciousfoods. 2Whichspottreatstouriststofreedesserts? A.Wharf41. B.TheMissionBay. C.TheBakerBeach. D.GoldenGateBridge. 3WhatcanweinferabouttheJapaneseTeaGarden? A.ItsteaisfromJapan. B.Itisthebestteahouse. C.Itisaquietplace. D.ItwasbuiltbyJapanese.
Itisnowpossibletowatchlivesportontelevisiononanydayoftheweekandthepresentamountofreportingwillundoubtedlyincreasefurtherinyearstocome.Thisiscertainlyhavinganinfluenceonthelivesportseventsthemselvesandtherearebothbenefitsandshortcomingstothis. 1ForonethingwithdigitalbroadcastingtherearenowmanymoreTVchannelsthantherewereeventenyearsago.Moreoversporthasbecomeanimportantformofentertainmentattractingbothmenandwomen. Whatarethebenefitsofthistelevisedsport?2Largefootballclubsbenefitfinancially财政上fromTVincomeandthetopplayerscanbewellpaid.Lesspopularsportsalsoreceivemoneythatcanbeusedintrainingandadvertising.What'smorethereisahealthbenefittosomeofthepopulation.3. Howevertherewillbesomedisadvantagesifsomuchsportisontelevision.Consideringfootballagainmanysmallclubshavesufferedfinanciallossesrecentlyastheycannotcompetewiththelargeones.4Fewerpeoplewatchlivematchesnowadayspreferringtowatchfromthecomfortoftheirlivingroom.Andticketpriceshaverisengreatly. Inawordwatchinglivesportontelevisionhasbothgoodandbadeffects.Televisedsporthascreatedmanychancesandbenefitedcertainpeopleandclubsverymuch.5. A.Whyhastherebeensuchgrowthintelevisedsport? B.Whyaretheresomanybenefitsofwatchinglivesportontelevision? C.Televisedsportcanbehelpfulinincreasingpeople'svalueofteamwork. D.Therehasbeenageneralfallinginticketsalesespeciallyamongsmallerclubs. E.Throughtelevisedsportmorepeoplehavebecomeinterestedinactuallyplayingsport. F.Oneobviousadvantageoftelevisedsportisthemoneyprovidedbytelevisioncompanies. G.Howeverithasalsobeenresponsibleforchangingthenatureoflivesportseventsforever.
It'snothingunusualforpeopletomultitasknowadays.Buttheabilitytodoanumberofthingsatthesametimecouldbedifferentbetweenthetwosexes. AteamofUKresearchersrecentlycomparedtheperformancesof120womenand120meninacomputertestaboutswitching转换betweentasksofcountingandshaperecognition. Menequalledwomenwhentasksweredoneoneatatime.Butwhenthetasksweremixeduptherewasacleardifference.AccordingtothepaperpublishedinthejournalBMCPsychologybothwomenandmensloweddownandmademoremistakesastheswitchingbecamemorerapid.Butmenwereslowertaking77percentlongertoanswerwhilewomentook69percentlonger. Tomaketheexperimentmoreconnectedtoday﹣to﹣dayliferesearcherstriedasecondtest.Agroupofwomenandmenweregiveneightminutestocompleteaseriesofeverydaytaskssuchasfindingrestaurantsonamapdoingsimplemathproblemsansweringaphonecallordecidinghowtheywouldsearchforalostkeyinafield. Onceagainwomenperformedbetterthanmeninthetestespeciallyinthekey﹣searchingtask. Wheredowomengettheabilitytokeeporganizedunderpressurebetterthanmen?Researchersbelievethatithasitsoriginsinevolution进化.Inancienttimeswomenhadtokeepaneyeonchildrenwhilecookingmeals.Meanwhilemenonlyneededtofocusonhunting. Howeveraswithallstudiestheresultsdon'tnecessarilyapplytoeverysinglepersonintheworld.Wedon'tmeanthatmencan'tmultitaskorthatonlywomencanresearcherKeithLawsoftheUniversityofHertfordshireUKtoldBBCNews.Wearesayingthattheaveragewomanisbetterabletoorganizehertimeandswitchbetweentasksthantheaverageman. 1Inthetestsresearchersfoundthat. A.womenwerebetteratswitchingbetweentasksthanmen B.womenmademoremistakesthanmenwhenmultitasking C.menwerebetteratcountingandshaperecognitionthanwomen D.mencompletedaseriesofdailytasksmorequicklythanwomen 2Whatisthemainpurposeofparagraph6? A.Togiveadviceonhowtoimprovetheabilitytomultitask. B.Toshowhowmenandwomenthinkandrespondotherwise. C.Tocomparetherolesofmenandwomeninhumancommunities. D.Toexplainwhymenandwomenperformdifferentlyinmultitasking. 3WhichofthefollowingwouldKeithLawsmostprobablyagreewith? A.Allwomenareborntobegoodatmultitasking. B.Somemenareasgoodatmultitaskingaswomen. C.Menshouldn'tdojobsthatcallformultitaskingskills. D.Everywomanisbetterabletomultitaskthaneveryman.
假定你是李华.你通过用英语写信的方式和在北京留学的James建立了深厚的友情.请你用英语给他写封信谈谈写信给你带来的好处内容包括 1.交际方面 2.英语学习方面 3.思想认识方面. 注意 1.词数100左右 2.可以适当增加细节以使行文连贯.
已知曲线C的极坐标方程是ρ2＝4ρcosθ+6ρsinθ﹣12以极点为原点极轴为x轴的正半轴建立平面直角坐标系直线l的参数方程为t为参数． I写出直线l的一般方程与曲线C的直角坐标方程并判断它们的位置关系 II将曲线C向左平移2个单位长度向上平移3个单位长度得到曲线D设曲线D经过伸缩变换得到曲线E设曲线E上任一点为Mxy求的取值范围．
若将n粒玉米种子置于__中使其萌发得到n株黄化苗．那么与萌发前的这n粒干种子相比这些黄化苗的有机物总量和呼吸强度表现为
培养胡萝卜根组织可获得试管苗获得试管苗的过程如图所示． 回答下列问题． 1利用胡萝卜根段进行组织培养可以形成试管苗．用分化的植物细胞可以培养成完整的植株这是因为植物细胞具有． 2步骤③切取的组织块中要带有形成层原因是． 3从步骤⑤到步骤⑥需要更换新的培养基其原因是．在新的培养基上愈伤组织通过细胞的过程最终可形成试管苗． 4步骤⑥要进行照光培养其作用是． 5经组织培养得到的植株一般可保持原品种的这种繁殖方式属于繁殖．
动物初次接受某种抗原刺激能引发初次免疫应答再次接受同种抗原刺激能引发再次免疫应答．某研究小组取若干只实验小鼠分成四组进行实验实验分组及处理见下表． 回答下列问题． 1为确定ABCD四组小鼠是否有免疫应答发生应检测的免疫活性物质是填“抗体”或“抗原”． 2再次注射抗原后上述四组小鼠中能出现再次免疫应答的组是．初次注射抗原后机体能产生记忆细胞再次注射同种抗原后这些记忆细胞能够． 3A组小鼠再次注射抗原甲一段时间后取血清血清中加入抗原甲后会出现沉淀产生这种现象的原因是． 4若小鼠发生过敏反应过敏反应的特点一般有答出2点即可．
Itseemsthatartificial1intelligentcandomuchmorethanwhatwehaveeverimagined.Fromcontrollingthelightinginourhomesto2helpusorderpizzaAIhasbecomeanimportantpartofoureverydaylife.Butwhataboutthemorecreativeworksofmankind?Artmusicpoetry﹣theseareinspirednotbylogicorreason3byemotion. In2017researchersinSwitzerlandcreatedthedeepartificialcomposerDAC4cancreateoriginalmusicallby5it.Thescientiststrainedittolistentoover2000differentfolksongsand6baseonthisinputtheAItaughtitselfhowtogetthepitch音高andtimingandchoosetherightnotes.BesidesmusicAIalready7entertheworldofpoetryaswell.In2018ChineseandJapaneseresearcherswroteanAIprogramthatusesimagestowritepoems.Thenthepoemsweresentto500humanjudgeswhowereaskedtotell8theywerewrittenbyahumanoracomputer.Theresultshowedthatas9as200judgesmistakenlythoughttheywerewrittenbyahuman. Soifyouwere10artistoramusicianwouldyouwatchout?
过点M12的直线l与圆Cx﹣32+y﹣42＝25交于AB两点C为圆心当∠ACB最小时直线l的方程是．
如图在圆心角为直角的扇形OAB区域中MN分别为OAOB的中点在MN两点处各有一个通信基站其信号的覆盖范围分别为以OAOB为直径的圆在扇形OAB内随机取一点则此点无信号的概率是
WaystoFightandOvercomeLaziness Youreadproductivitytipsyou'veusedamillionto﹣dolistappsandyoupromiseyourselfeverymonththatyou'regoingtostartbeingproductivebutitneverhappens.Here'showtobreakthecyclewhenyoufeellikeyourproblemisjustlaziness. SimplethingsfirstIt'simportanttogetstartedwiththetaskyou'rewillingtoperforminordertofightlaziness.1Doingsowillhelpyoutobreakyourinnerresistance. Step﹣by﹣step2Anditwillkeepusmotivatedtoperformthesetasksoneaftertheotherinarelaxedmanner.Onceyouhavecompletedonesub﹣taskyoucantellyourselfthatyou'reonarollandthatyouwillsoonhavefinishedthenextsub﹣tasksaswell. RemovedistractionsWhateveritisthatdistractsyouTVtheInternetetc.removeit!3Makesurethatonceyouhavestartedwithoneofyourtasksyouwillnotgetdistractedfromitbyanymeans. RewardyourselfEverytimeyoumanagetoovercomelazinessandsuccessfullycompleteataskyoushouldrewardyourselfasthiswillgiveyoupositivefeelingaboutmakingeffortstogetthingsdone.4Littlerewardforsmalleffortsandviceversa反之亦然. Don'tgiveupIt'sonethingtofindyourmotivation.5Ratherthanlettingdifficultiesdemotivateyouseethemforwhattheyareandrefusetobebeatenbythem.You'renotaloneandstayingfocusedonworkingthroughchallengesisoneofthebestwaystofightthem. A.Turnoffdistractionsandfocusonyourgoals. B.Justmakesuretoadapttherewardtotheeffortsyoumade. C.Alistofweeklygoalswillhelpyoustayfocusedandmotivated. D.Amethodthathelpsyoudosoistostartwiththesimplethingsfirst. E.Occasionalrewardswillsweetenthetasksandhelpkeepyouontrack. F.Butit'squitesomethingelsetokeepitgoingwhenrunningintodifficultproblems. G.Breakingdowntasksintosmallertaskshelpsustoreducethepressureofdeadlines.
JapanesetechnologygiantToshibahasbuiltahugecleanfactoryfarmwhereitisgrowingvarioustypesoflettuce莴苣leaveswithoutsunlightorsoilforsaleinitsnewhealthcarebusiness. Locatedinadisused21000﹣square﹣footelectronicsfactoryinYokosukaToshibaannouncestohavecreatedaperfectbacteria﹣freeenvironmentwhereitwillgrowthreemillionbagsoflettuceayear. CompletelycutofffromconditionsoutsidethetemperaturecontrolledtanklettuceinspectorswearfullbodysuitswhilemakingnotesonthequalityandgrowthoftheleavesontheiriPadsinordertopreventtheairaroundtheplantsbecomingcontaminated. Eachplantisgivenman﹣madelightingtotrickitintobelievingitisexposedtosunlightwhilevitaminandnutrientsareputdirectlyintoitsrootsmeaningthelettucedoesnotneedsoil. Toshiba'snewhigh﹣techfarmmayproducetheworld'shighestqualitylettuce.Thefinalproductwillbefreeofanyformofbacteriaorinsectlifebeforebeingplacedintosealed密封的bagswhichshouldensuretheproducthasalongershelflifethanotherlettuces. Thegardeningtechniqueaimstohaveabacteriaamountofnomorethan1/1000th﹣muchlowerthanthatfoundinnormalgardeningsoil. Toshibaaimstoharvestthreemillionbagsofleaflettucebabyleafgreenscabbagesandotherkindsofvegetableseveryyear﹣witheachbaglikelytocostpeople£1. Themostimportantthinginorganicvegetablesthelettucerequiresnopesticides杀虫剂butisexpectedtohaveasimilarshelftoplantsthathavebeenheavilytreatedwithchemicals. ThelettucefactoryisnomarketingtrickbyToshibahowever.Insteaditrepresentsthecompany'slatestattempttoexpanditstechnology﹣ledbusiness. Therearealreadyplansforthetechnologygianttobuildsimilarfactoriesaroundtheworldoverthecomingyearsanditwillalsobesellingthehightechequipmentthatallowsfactoriestoproducesimilarproductsofexceptionallyhighquality. 1WhatisthepurposeofToshibainplantingthenewtypeoflettuce? A.Todoscientificresearch. B.Toincreasetheproduction. C.Toimprovethehealthcare. D.Tomakeaprofit. 2Theunderlinedwordcontaminatedinparagraph3canbereplacedby. A.polluted B.reduced C.controlled D.dried 3WecanlearnfromthetextthatthelettuceinToshiba'sfactoryfarm. A.needssoiltogrow B.hastobeexposedtosunlight C.canbestoredlongerthanthenormal D.gainsvitaminsandnutrientsfromman﹣madelighting 4Whatisthetextmainlyabout? A.ThebriefintroductionofToshiba. B.Theprocessofplantinglettuce. C.Thedevelopmentofafactoryfarm. D.Thenewwayofplantinglettuce.
ScientistsattheUniversityofBonncarriedoutextensiveresearchtoshowthatthewaterdropsrollingoffalotus莲花leafcarryawaydirtleavingthesurfaceperfectlyclean.ThisphenomenahasbeennamedtheLotusEffectandworksbestonroughsurfaces. Contrarytopopularbelieflotusleavesarenotsmoothatall.Whenexaminedunderapowerfulmicroscopetheleafcellsshowabumpysurface.Thatmakesthesurfacerough.Asaresultdirtrestsonlyonthetipsofthewaxcrystals蜡晶体coveringtheleafsurface.Theroughnessreducesthecontactareabetweenthedirtandtheleafsurface.Aroughsurfacestructurewithwaxcrystalsmakesitimpossibleforwatertostick.Duetothefriction摩擦力thewatercontractsatonce.Itformsroundwaterdropstominimizethecontactareawiththeroughwaxyleafsurfaceandrunsofftheleafveryquickly.Sincethedirtonlyrestsonthetipsofthewaxcrystalstheystickmorestronglytothewaterdropsthantotheleafsurfaces.Theyarewashedawaywhenthewaterfallsontheleaves. Onsmoothleavesthedirtispushedfromonepartoftheleaftotheother.Thisisbecausethedirthasalargercontactareawheretheycanrestcomfortablyontheflatsurface.Wemustalsokeepinmindthatwaterusuallyspreadsandonlypartiallyrunsofftheleaves﹣thattooonlyiftheleafistilted!Thedirtmaygetdrivenbuttheyaremainlydisplacedfromonesideoftheleaftotheother. ScientistssaythattheLotusEffectisparticularlybeneficialforithelpstoprotectthelotusleavesfromharmfulbacteria.Thedirtontheleavesoftencontainstinydiseasecausingfungiandbacteria.Whilemostofthebacteriagetwashedoffthefewthatremaineventuallydiesincetheydonotgetthewatertheyrequireforsurvivalandgrowth. 1WhatisLotusEffect? A.Theself﹣cleaningfeatureoflotusleaves. B.Thelotussurfaces'abilitytokillharmfulbacteria. C.Thedirtleavingofflotusleaveswiththehelpofwind. D.Lotusleavesmakingwaterdropsfromthedirtonthem. 2Whatdoestheunderlinedwordbumpyinparagraph2probobalymean? A.Flat. B.Bended. C.Flexible. D.Rough. 3Whyarewaterdropsunabletostayonlotusleaves? A.Thecontactareabetweendropsandleavesistoolarge. B.Thesmoothleafsurfacemakeswaterdropsrolldown. C.Theroughandwaxyleafsurfacereducesthefriction. D.Thewaterdropsfallontheleavesatatoohighspeed. 4WhatisthebenefitofLotusEffect? A.Itcanprotectthelotusfromsunshine. B.Itcanhelpthelotusgrowhealthily. C.Itcanmakethebacteriamoreandstronger. D.Itcanhelpthelotusleaveskeeptherequiredwater.
假定你是中学生李华你作为学校代表访问了加拿大的姐妹学校现已回国.请你给该校校长Mr.White发一封邮件表示感谢内容包括 1.感谢对方接待 2.访问期间收获 3.邀请对方来访. 注意 1.词数80左右 2.可适当增加细节以使行文连贯.
显然你应当为自己的行为向老师道歉.obviousapologize
如图一简单几何体ABCDE的一个面ABC内接于圆OGH分别是AEBC的中点AB是圆O的直径四边形DCBE为平行四边形且DC⊥平面ABC． Ⅰ证明GH∥平面ACD Ⅱ若AC＝BC＝BE＝2求二面角O﹣CE﹣B的余弦值．
玉米是一种二倍体异花传粉作物可作为研究遗传规律的实验材料．玉米子粒的饱满与凹陷是一对相对性状受一对等位基因控制．回答下列问题． 1在一对等位基因控制的相对性状中杂合子通常表现的性状是． 2现有在自然条件下获得的一些饱满的玉米子粒和一些凹陷的玉米子粒若要用这两种玉米子粒为材料验证分离定律写出两种验证思路及预期结果．
FourEverydayThingsHurtingYourHealth Youreverydaybehaviorsmaybeholdingyouback.Howeverperhapsyoudon'tevenknowit.1aswellassomeexpertadviceonwhattodoinstead. 2.Itcanalsodecreaseyourbrain'sabilitytofunctionthusresultinginpoorperformanceatworkandlongerreactiontimebehindthewheel.Expertsrecommendpracticingarelaxingbedtimeroutineliketakingabathcuttingdownoncaffeineandalcohol.Anothertrickistosticktoaconsistentsleepschedule. Studieshaveshownthatsittingforextendedperiodscanhavesignificantnegativeimpactsonphysicalandmentalhealth.Youdonthavetorunamarathontogetactivethough.WorksmallexercisesintoyourdaylikestandingduringTVadvertisementsorparkingyourcarfarawayfromanentrance.3. Isituneasytolockyourcellphoneawayforasolid60minutes?Socialmediaisn'thelpingeither.Expertsrecommenddeletingsocialmediaappsorhidingthem.4andmakingapointofdoingsomethingtogroundyouinthepresentmomenteachday. Intoday'scompetitivesocietyit'shumannaturetotakeonasmanytasksaspossible.Butcontinuousresponsibilityandrushingfromonejobtothenextisabadhabitthatcanleadtoeventualburnout.5especiallythosethatyouhavenotimetoaccept. A.Thesmallcanmakeahugedifference B.Badsleepcanleadtoavarietyofharms C.Goodeducationbackgroundisn'thelping D.Thismeanspracticingtheartofsayingyes E.Expertssuggestpolitelyturningdowninvitations F.Beawareofsomehabitswithanegativeimpactonyourhealth G.Theyalsosuggestchargingyourphoneoutsideofyourbedroom
液体中的部分分子因为具有足够的能量而脱离液面直接进入空气中这是蒸发的本质其实固体表面也有部分分子因为具有足够的能量而脱离固体表面直接进入空气中这是升华的本质．由此看来上述物态变化有着想通过的微观本质都是因为．
已知实数xy满足若z＝x﹣12+y2则z的最小值为
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