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如图,AB为⊙O的直径,点D在⊙O上,不与点A,B重合,点C是的中点,过点C作AD的垂线EF交直线AD于点E. (1)求证:EF是⊙O的切线; (2)若AB=5,sin∠BAC=,求线段AE的长...
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如图AB是半圆O.的直径C.为半圆上一点N.是线段BC上一点不与B.﹑C.重合过N.作AB的垂线交A
如图AB是⊙O.的直径半径OC⊥AB点D.是弧ACB上的动点不与
B.C.重合),DE⊥OC,DF⊥AB,垂足分别是E.F.,则EF长度( ) A. 变大
变小
不变
无法确定
如图AB为⊙O.的直径作弦CD⊥AB∠OCD的平分线交⊙O.于点P.当点C.在下半圆上移动时不与点
B.重合),下列关于点P.描述正确的是( )
A.到CD的距离保持不变
到D.点距离保持不变
等分
位置不变
已知AB是⊙O.的直径弦CD⊥AB于点G.E.是直线AB上一动点不与点A.B.G.重合直线DE交⊙O
如图AB是⊙O.的直径C.D.是圆上的两点不与A.B.重合已知BC=2tan∠ADC=1则AB=__
如图AB是⊙O.的直径C.D.是圆上的两点不与A.B.重合已知BC=2tan∠ADC=1则AB=__
如图AB为的直径点C.在⊙O上点P.是直径AB上的一点不与A.B.重合过点P.作AB的垂线交BC的延
已知AB是⊙O.的直径弦CD⊥AB于点G.E.是直线AB上一动点不与点A.B.G.重合直线DE交⊙O
如图AB是⊙O.的直径点C.在⊙O.上过点C.的切线与BA的延长线交于点D.点E.在上不与点B.C.
如图线段AB的长为10cm点D.是AB上的一个动点不与点A.重合以AD为边作等边△ACD过点D.作D
如图在⊙O.中AB是直径CD是弦AB⊥CD1P.是优弧CAD上一点不与C.D.重合求证∠CPD=∠C
在⊙O中AB为直径点C为圆上一点将劣弧沿弦AC翻折交AB于点D连结CD.1如图1若点D与圆心O重合A
A.B是⊙O上的两个定点P是⊙O上的动点P不与AB重合我们称∠APB是⊙O上关于点AB的滑动角.已知
如图AB是半圆O.的直径C.为半圆上一点N.是线段BC上一点不与B.﹑C.重合过N.作AB的垂线交A
如图AB是半圆O.的直径C.为半圆上一点N.是线段BC上一点不与B.﹑C.重合过N.作AB的垂线交A
如图AB为⊙O.的直径点C.在⊙O.上点P.是直径AB上的一点不与A.B.重合过点P.作AB的垂线交
如图AB为⊙O.的直径AB=2点在M.在QO上MC垂直平分OA点N.为直线AB上一动点N.不与A.重
如图AB是⊙O.的直径D.是⊙O.上的任意一点不与点A.B.重合延长BD到点C.使DC=BD判断△A
如图AB是⊙O.的直径C.D.是圆上的两点不与A.B.重合已知BC=2tan∠ADC=1则AB=__
在⊙O.中AB为直径点C.为圆上一点将劣弧沿弦AC翻折交AB于点D.连结CD.1如图1若点D.与圆心
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只用下列方法不能把下列物质区分开的是
近日在重庆“服役”51年的牛角沱嘉陵江大桥开始大修了这座跨越了半个多世纪的大桥是重庆主城首座城市大桥也是市级文物保护单位.其中大桥桥面部分的施工是大修工程的重点之一主要是进行行车道板改造.工程将拆除桥面现有的混凝土行车道板更换为钢桥面板.请回答下列有关问题 1钢桥面板的主要材料合金填“是”或“不是”选择该材料的原因是填字母序号. A.密度大B.硬度大C.导热性好 2桥梁外表面由于处于潮湿和酸性大气中容易腐蚀生锈.请写出用稀硫酸清洗铁锈的化学方程式. 3如果你是桥梁维护人员请说出一种防止钢铁生锈的方法.
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.作文中共有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Λ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. Thisismyfifthdayatthesummercamp.Lifeisn'texactwhatIexpected.WehavetogetupearlytomakeourbedsbeforeourteacherMissLicometoinspect.Afterbreakfastwehavesomeoffreetime.YesterdaymorningIwentfishingbuttheonlythingIcatchwasatreebranch.Intheafternoontherearedifferentactivitylikehorsebackridingandhiking.They'refunsonothingnewforme.Intheeveningeveryoneisassignedadifferenttasktogetdinnerready.YesterdayIwasinchargeofpreparethehotdogsbutIaccidentallydroppeditinthefire.Thebestpartofcampisatnightwherewesitaroundacampfireandtellstories.
化学变化有时也是五彩斑斓的下列哪些反应不涉及颜色的变化
水与人类的生产生活息息相关下列有关水的说法正确的是
MoneyspentonadvertisingismoneyspentaswellasanyIknowof.Itservesdirectlytoassistarapiddistributionofgoodsatreasonablepricestherebyestablishingafirmhomemarketandsomakingitpossibletoprovideforexportatcompetitiveprices.Bydrawingattentiontonewideasithelpsenormouslytoraisestandardsofliving.Byhelpingtoincreasedemanditensuresanincreasedneedforlabourandisthereforeaneffectivewaytofightunemployment.Itlowersthecostsofmanyservices:withoutadvertisementsyourdailynewspaperwouldcostfourtimesasmuchthepriceofyourtelevisionlicensewouldneedtobedoubledandtravelbybusortubewouldcost20percentmore. Andperhapsmostimportantofalladvertisingprovidesaguaranteeofreasonablevalueintheproductsandservicesyoubuy.Apartfromthefactthattwenty﹣sevenActsofParliamentgovernthetermsofadvertisingnoregularadvertiserdarepromoteaproductthatfailstoliveuptothepromiseofhisadvertisements.Hemightfoolsomepeopleforalittlewhilethroughmisleadingadvertising.Hewillnotdosoforlongformercifullythepublichasthegoodsensenottobuytheinferiorarticlemorethanonce.IfyouseeanarticleconsistentlyadvertiseditisthesurestproofIknowthatthearticledoeswhatisclaimedforitandthatitrepresentsgoodvalue. AdvertisingdoesmoreforthematerialbenefitofthecommunitythananyotherforceIcanthinkof. ThereisonemorepointIfeelIoughttotouchon.RecentlyIheardawell﹣knowntelevisionpersonalitydeclarethathewasagainstadvertisingbecauseitpersuadesratherthaninforms.Hewasdrawingexcessivelyfinedistinctions.Ofcourseadvertisingseekstopersuade. Ifitsmessagewereconfinedmerelytoinformation﹣andthatinitselfwouldbedifficultifnotimpossibletoachieveforevenadetailsuchasthechoiceofthecolourofashirtissubtlypersuasive﹣advertisingwouldbesoboringthatnoonewouldpayanyattention.Butperhapsthatiswhatthewell﹣knowntelevisionpersonalitywants. 1Bythefirstsentenceofthetexttheauthormeansthat. A.heisfairlyfamiliarwiththecostofadvertising B.everybodyknowswellthatadvertisingismoneyconsuming C.advertisingcostsmoneylikeeverythingelse D.itisworthwhiletospendmoneyonadvertising 2InthetextwhichofthefollowingisNOTincludedintheadvantagesofadvertising? A.Securinggreaterfame. B.Providingmorejobs. C.Enhancinglivingstandards. D.Reducingnewspapercost. 3Theauthorthinksthatthewell﹣knownTVpersonalityis. A.verypreciseinpassinghisjudgementonadvertising B.interestedinnothingbutthebuyers'attention C.correctintellingthedifferencebetweenpersuasionandinformation D.obviouslypartialinhisviewsonadvertising 4Intheauthor'sopinion. A.advertisingcanseldombringmaterialbenefittomanbyprovidinginformation B.advertisinginformspeopleofnewideasratherthanwinsthemover C.thereisnothingwrongwithadvertisinginpersuadingthebuyer D.thebuyerisnotinterestedingettinginformationfromanadvertisement
I'velearnedseveralforeignlanguagesasanadultandwasabletolearnFrenchtofluentconversationin17days. In2005IstayedwithaFrenchfriendinaFrenchvillage.NooneinthevillagespokeEnglishandmyfriendrefusedtospeakEnglishaswell. IsetuparoutinewhereIdidthesamethingseveryday. InthemorningIpracticedwritingvocabularyfor2hours.Ibelievewritingthingsoutisthebestwaytomemorizethings. WhilewritingIwouldlistentoFrenchlearningMP3s.It'sreallyhelpfultohearotherstudentsmakemistakesthatyoucanlearnfromjustlikearegularclassroomenvironment. IhadlunchwithmyFrenchfriendseveryday.AstheyrefusedtoslowdownwhenspeakingtomeinFrenchitwastolearnortostarve! IntheafternoonIreadCharlieandtheChocolateFactoryinFrench.Readingthechildren'sbooksyoureadasachildisagreatwaytolearnnewlanguages.Firstlythelanguageusedissimpleandsecondlyknowingthestoryhelpsyoutoguessthemeaningofnewwordsandavoidusingadictionary. IspentanhourwritingbasicessaysaboutthingsthatalwaysgetaskedlikeWhereareyoufrom?Whatdoyoudo?whichIhadmyFrenchfriendcheckforerrors.Bylearningready﹣madeanswersyoupracticewhatyoulearnedandbuildupyourconfidence. Anothergoodtipistolearnthefillerwordswhichpeoplesaybetweensentencesbuthavenorealmeaningallowingyoutobuytimeinconversation. After17daysIwenttoPariswhereImetagirlinacoffeeshop.WhenItoldherIhadbeenlearningFrenchfor17dayssheinsistedthatIhadlivedinFranceforatleastayear. 1Thewritermaycomefrom. A.France B.Germany C.China D.theUSA 2WhichofthefollowingisNOTwhatthewriterdoesinlearningFrench? A.ShewrotenewFrenchwordsonebyoneagainandagaineverymorning. B.ShewouldlistentoaFrenchteachingclassbyMP3whileshewaswriting. C.Shehadsupperwithherfriendseverydaypracticetalkingwiththem. D.Shewroteanswerstosomeusualquestionstobuildupherconfidence. 3Whatisthepurposeofthewritertowritethisessay? A.Totellpeoplethatshewasaverygoodlanguagelearner. B.Tosharewithpeoplesomemethodsoflearningalanguage. C.Tokeeparecordofherexperienceoflearningalanguage. D.Totellpeoplethatitwasnoteasytolearnanewlanguage.
假如你在友好学校CloverportSchool夏令营期间观摩了当地小镇的一个节日活动请根据其中的一项活动宣传单完成一则英文报告.每空限填一词. Helloeverybody!I'msogladtoexperiencetheSacajawea1inthetownofCloverport.It'sacommunityfestivaltobringpeopletogether.TeenMr.Cloverportisacompetitionfor2fromthirteentosixteenyearsold.MynewfriendTristanpaid3dollarstoenterit.Hewasreallyexcitedaboutit.Theyhavetowearhomemadeclothesinsteadofthoseboughtfroma4.IthinkthespiritofDIYreallymatters.Tofollowtherulestheyarenot5tosmokedrinkwineorspeakrudely.Theyshouldbewell﹣behaved.Thankyou!
如图是向氢氧化钠溶液中加入稀盐酸反应的微观示意图以下说法错误的是
Itwasourschool'syearlydancingshow.I1beexcitedthatIwaschosenbytheteacherthistimealthoughIdidn'thaveanyexperienceofdancingforashow.Iwoulddanceinfrontofallthestudentsand2teacher.Itmademeveryproud. HoweverIwasabitsad3myfatherhadnotimetowatchmedance.He4invitetohaveabusinessmeeting.Iknewthatmyfatherwouldsurelycometomyshowifhecould.5luckymymotherandmyeldersisterwerestillcomingtowatchmyshow. 6thebeginningofthedayIwasverynervous.AfterchangingintothedressandgettingmymakeupdoneIfelt7relax.ThenIwentontothestagebravely.Iwasverygladtoseemymotherandsistersittingin8secondrow. JustbeforethelightsturneddarkIsawmyfatherrushintothehallandtaketheseatbesidemymother.9apleasantsurpriseitwas!Thesightofmyfathermade10Ismile.Ibegandancingconfidently.Soonaftertheshowmyfamilycamebackstagetocongratulateme.Iwassohappyandluckytohavemyfamily'ssupport.
某同学去医院检査身体医生建议他多吃“水果和蔬菜”你推测医生的意图是让该同学补充
Theworldhasaplasticsproblem.Andnotjustwithbottles.Straws吸管toothbrushestoys﹣allkindsofplasticsareplacedinlandfills.Thereare5billiontonsofplasticwasteintheworld.Landfillshavealargepartofit.By2050theycouldhave13billiontons. Muchofplasticrubbishfindsitswayintotheocean.Scientistssay165milliontonsofplasticpiecesarefloatingaroundoutthere.Andmostplasticwon'tdisappearitself.Itwillremainintheoceanforever.Whalesgetcaughtinplasticfishingnets.Birdsdiebecauseofeatingplasticstrawsandbottlecaps.Itendangersoceanlife.Plasticrubbishevenendsupinthefoodweeat. Governmentsarerealizingthatrecyclingmaynotbeenough.Theyaretakingmoreactions.Thoughitishardworkitisstillasolvableproblem.InBritainpeoplearenotallowedtouseplasticbagsexceptinhospitals.ScotlandandseveralcoastalcitiesintheUSstoppeoplefromusingplasticstrawsaswell.TheUSalonethrowsawaysome500millionplasticstrawsaday.That'senoughtocircletheEarthtwice.SayingnotoaplasticstrawisaneasywaytomakeabigdifferenceDanaLofflinwhostartedsaid.Dowereallywanttopassontoourchildrenaworldharmedbyplastic? Peoplehavefoundsometastywaystoreducewaste.AcompanyinIndiamadethefirst﹣everspoonthatpeoplecaneat.Youdon'thavetoeatthespoon.Youcanthrowitaway.Itdecomposes分解injustafewdays.DavidEdwardsascientistatHarvardUniversitydesignedaneatablebagwhichcanprotectthefoodordrinkinside.Itisadeliciousreplacementforplasticones. 1Accordingtothewritebirdsdiebecausethey. A.eatbottlecapsandstraws B.getcaughtinfishingnets C.feedonoceananimals D.havethespoonsinIndia 2TheunderlinedwordendangersinParagraph2probablymeans. A.brings B.loses C.harms D.saves 3Thepurposeofthepassageismainlyto. A.introducesomewaystorecyclewaste B.tellreadersabouttheproblemwithplastics C.compareairpollutionandplasticpollution D.describehowtheUSisreducingplasticwaste 4Fromthepassagewecantellthattheplasticsproblem. A.istoobigforpeopletosolve B.canbesolvedbyrecyclingalone C.canbesolvedbutitwontbeeasy D.willhavetobesolvedbyfuturescientists
小明同学设计了如下实验方案分离NaCl和CaCl2两种白色粉末的混合物W请回答下列问题 1试剂A的化学名称是. 2操作Ⅱ需要用到除烧杯玻璃棒之外的玻璃仪器还有. 3沉淀B洗涤后加入稀盐酸的化学方程式是该反应的反应类型是.
Jealousofthekidsatschoolwhoaresmarterthanyouandseemtolearnmorequickly?Don'tworry.1 2HoweveraccordingtoarecentstudyIQcanrise﹣﹣notjustbyoneortwopointsbutbyasmanyas21points! ScientistshavefoundthatIQchangesarelinkedtochangesinpartofthebraincalledgraymatterwhichwasseentogrowandbecomedenserinthebrainsofpeoplewhoseIQsimprovedgreatly.3Oneistotrainyourshort﹣termmemory.Previousresearchhasproventhatshort﹣termmemoryisthebasisforintelligencesotryingtorecognizeorretellsomethingthatyouhaveseenorheardcanhelpraiseyouroverallbrainpower.4 Agoodnight'ssleepwillalsohelpimproveyourconcentration.5Ithelpsyoustayfocusedforlongerthenextday. Scientistshavealsofoundthatexercisehelps.Walking30minutesadayfivetimesaweekanddoingexercisewillhelpyoubecomemoreknowledgeableaswellashealthierandfitter. A.Thereareseveralwaysofincreasingyourbrain'sgraymatter. B.Yourbraindealsmoreefficientlywiththingsyoutrulylike. C.Withabitofbraintrainingthechancesarethatyoucanbeassmartastheyare. D.Somaybeit'sagoodideatogetyourbrainintrainingrightaway. E.Gettingenoughsleepislikepushingtheresetbuttoninyourbrain. F.Themoreyouworkonitthebetteryouwillbecome. G.Peopleusedtoassumethataperson'sIQwasunchangeable.
菠菜中含有草酸将草酸晶体隔绝空气加热使其完全分解生成水和碳的氧化物.为了探究上述反应生成的碳的氧化物成分同学们提出以下猜想. 1猜想与假设 猜想一只有CO猜想二只有CO2猜想三 2某同学设计了如图1所示实验验证猜想 ①无水草酸晶体熔点较低加热到182℃便开始熔化189.5℃分解.根据此信息你应选择的加热装置为图2中填“A”或“B” ②该装置中乙的作用为末端气球的作用为 ③实验中下列操作的先后顺序是 a.点燃加热装置中的酒精灯b.点燃丙处的酒精喷灯c.检查装置气密性d.装入药品 ④若甲试管和丁试管内溶液都变浑浊丙处玻璃管内的黑色固体变成红色则猜想正确.
1TotallyWildHotelisspecialbecauseof. A.itshighprice B.itsgoodbreakfast C.thelovelygiraffes D.theoldbuildings 2AccordingtothetextpeoplecaninKenya. A.cheeroncamelsinLamuOldTown B.havebreakfastwithzebrasinTotallyWildHotel C.seelionszebraselephantsinEastNationalPark D.watchthebrightpinkbirdsnearLakeNakuru 3willmostprobablybeinterestedinthetextabove. A.Peoplewhoenjoytravelling B.Scientistswhostudybirds C.Playerswhoaregoodatrunning D.Peoplewhohaveapainintheneck
氯碱工业是指用电解饱和NaCl溶液的方法来抽取NaOHCl2和H2并以它们为原料生产一系列化工产品电解饱和NaCl溶液的化学方程式为2NaCl+2H2OCl2↑+H2↑+2NaOH 请计算 1烧碱中三种元素的质量比为. 2用这种方法制备40t烧碱需要食盐的质量. 3若用25%的食盐溶液按照上述方法电解并制取40t烧碱完全电解后所得溶液的质量分数.假设生成的烧碱全溶计算时若除不尽保留1%
在宏观微观和符号之间建立联系是化学学科的特点. 1某物质由氢元素和氧元素组成其分子中原子个数比为11该物质发生分解反应的化学方程式为. 2根据常见元素和原子团的化合价下列四种物质的化学式书写不正确的是. A.氧化钠Na2OB.氧化铝AlOC.硫酸钠Na2SO4D.氯化铁FeCl2 3镁钠铝三种金属的活动性由强到弱的顺序是请写出铝离子的离子结构示意图.
生活中处处都有化学下列说法正确的一项是
Iloveagoodmurdermystery.Itisso1towatchorreadanexcitingandinterestingdetectivestoryandtrytosolvethe2yourself.AgathaChristieisundoubtedlyqueenofthedetectivestoryconsideringshe3overeightybooks.Manypeoplehavefalleninlovewithher4﹣﹣﹣﹣﹣HerculePoirotafamousBelgiandetectiveandMissMarpleanoldladywhoisalsoanamateur5. AsIamabig6ofAgathaChristieIwasexcitedto7herhouseinDevoncalledGreenway.Itravelledtoher8bysteamtrain.Wewentthroughadarktunnelandtherewaslotsofsmoke.Itwasa9settingforamurderlikeinherfamousnovelMurderontheOrientExpress.10allthepassengersarrivedsafely! AfterapleasantwalkthroughthewoodsI11thesplendidhouse.IdidatourandIlovedseeingwhereshewroteher12.Manyfirsteditionswereondisplayinarevolving旋转的bookcase.Howevermy13partoftheestate房产wastheboathouse.Therewasalovelyviewoftheriver14theboathousealsoservedamorespecialpurpose﹣﹣﹣inspirationforacrime15.InthePoirotnovelDeadMan'sFollyagirl'sbodyis16intheboathouse.Theyeven17theTVadaptationofthebookatGreenway. Ireally18myvisittoGreenway.Itwassucha19placeandIwasinterestedinseeingwhereAgathaChristiewas20towritesomanyexcitingstories. 1A.upset B.serious C.successful D.fun 2A.doubt B.problem C.murder D.method 3A.read B.wrote C.saw D.contributed 4A.creations B.inventions C.discussions D.reasons 5A.guard B.detective C.creator D.spy 6A.guide B.fellow C.fan D.gift 7A.watch B.rebuild C.explode D.visit 8A.house B.family C.hometown D.site 9A.perfect B.central C.colorful D.direct 10A.Sadly B.Fortunately C.Hopefully D.Surprisingly 11A.fetched B.got C.reached D.mentioned 12A.posts B.poems C.letters D.books 13A.personal B.useful C.rewarding D.favourite 14A.or B.and C.but D.for 15A.scenery B.sight C.view D.scene 16A.dissolved B.tended C.found D.buried 17A.developed B.filmed C.adapted D.affected 18A.enjoyed B.treasured C.exploited D.focused 19A.shocking B.beautiful C.skilful D.helpful 20A.inspired B.disappointed C.marked D.honored
假定你是李华你校英文报心理与健康栏目拟刊登一篇文章为高三备考的学生如何安排课余生活和释放心理压力提出建议.请你为此栏目写一篇英语短文要点如下: 1.高三学习的挑战和困难 2.如何安排课余生活 3.如何释放心理压力 注意:1.词数100左右; 2.可以适当增加细节以使行文连贯; 3.开头语已为你写好. LifeinSeniorThreeisnoteasy.
硫酸和盐酸既是实验室常用的试剂也是重要的化工原料.它们既有相似之处又有不同之点. 1它们水溶液的pH都7填“大于”“小于”或“等于”. 2它们都能除铁锈写出盐酸与铁锈主要成分反应的化学方程式. 3它们都能与碱反应生成盐和水该类反应叫反应. 4打开两瓶分别盛有浓硫酸和浓盐酸的试剂瓶瓶口出现白雾的是.
InthesmalltownsoftheUnitedStatesinthe1nineteencenturythegeneralstorewas2everyoneboughtthethingshecouldn'tmake3growathome.Whatthestoressold4tellagreatdealabout5lifeatthattime.Peopleboughttoolsthattheyneededforfarmwork;saltsugarand6foodsthatthefarmdidn'tproduce;articlesofclothingthattheycouldn'tmake7;shirtsforthemen;orclothesforthechildren.Lifewassimplethen.Onefeelsthatpeoplewere8thankforwhattheyhadandthattheylookedforwardwithcourageto9thefuturebrought.Itwouldbeinterestingtoknowhowtheywouldfeelaboutthelifetoday.Woulditseemtothemthatlifeistoocomplex?Wouldtheyenjoy10livealifeaswedonow?
MoviefansknowthattheiractionheroSupermandoesnotreallyfly.AndinthemovieSupermanReturnsanothervisualtrickisplayedonviewers.Themantheyseeflyingisnotreal.Heiswhatiscalledavirtualactor.Thefirststepincreatingthisdigitalactoristohavearealpersonstandinaroomcalledalightstage.Acomputerthencapturestheoutlinesandshapesofhisfaceandrecordshowtheythrowofflight.PaulDebeveciswiththeInstituteforCreativeTechnologiesattheUniversityofSouthernCalifornia. Wecanlightthemwithveryspeciallycomputer﹣controlledillumination照明andtakephotosofthemfromsevendifferentviewpointswithhighqualitydigitalstillcameras. Mr.Debevecispartofateamworkingtocreatecomputerizedimagesofpeopleobjectsandenvironmentsthatlookandactreal.ThelightstagepermitsactorstobeturnedintodigitalversionsofthemselvesmuchlikethebluecreaturesinthemovieAvatar.Therealworldcouldsoonbeusingasimilartechnology.ComputerexpertsattheInstitutearedevelopinga3﹣Dvideoteleconferencingsystem.Itwouldsendavideoimageofapersonintoameetingroom.Thatimagewouldbeabletoworkwiththepeopleintheroomwhowouldseeitin3﹣Dwithoutspecialeyeglasses.PaulDebevecsays: Thepersonwhoisbeingtransmittedtoaremotelocationcanactuallylookaroundatthepeopleintheroomandeverybodyinthatroomknowswhothey'relookingat.Andthat'ssuchafundamentalpartofhumancommunication. Hebelievesthebusinessworldwillbegintouse3﹣Dvideoteleconferencinginthenextfiveyears.It'salsoamediumwithwhichyoungpeopletodayareparticularlycomfortablehesaid.Ademonstrationofaninteractionbetweenanearthquakesurvivorandstudentsmaybepossibleinayear.In10yearswemaybeabletoplay3﹣Dvideogameswithoutspecialglasses. 1WhydoestheauthormentionthemoviesSupermanReturnsandAvatarinthepassage? A.Tocomparetheirdifferentstyles. B.Toexplain3﹣Dfilm﹣makingtechnology. C.Toattractmorereaderstowatch3﹣Dfilm. D.Todescribetheoriginof3﹣Dfilmindustry. 2Whichofthefollowingshowshowavirtualactorismade? a.arealactorstepsinsidealightstage. b.anactoriscreatedintodigitalversion. c.photosaretakenfromdifferentaspects. d.howtheactor'sfacereflectsthelightisrecorded. e.acomputermakessurehowtheactor'sfaceisfilmed. A.a→e→d→c→b B.a→c→e→d→b C.a→e→c→f→b D.e→d→c→a→b 3Whatistheauthor'sattitudetowards3Dtechnology? A.Cautious B.Positive C.Skeptical D.Critical 4What'sthemainideaofthetext? A.3﹣Dgoesfrommoviestorealworld. B.3﹣Dfilmbecomespopularworldwide. C.3﹣Dteleconferencingsystemcomesintobeing. D.3﹣Dgameswithoutspecialglassesbecomestrue.
ScientistsinArgentinahavecreatedtheworld'sfirstcowwithtwohumangenesthatwillenableittoproducehuman﹣likemilk. Geneticengineeringwasusedtointroducethemothers'milkgenesintotheanimalbeforebirthaccordingtotheNationalInstituteofAgribusinessTechnologyinBuenosAires. Asanadulttheclonedcowwillproducemilkthatissimilartohumansinwhatwillproveadevelopmentofgreatimportanceforthenutritionofinfantssaidtheinstitute.TheclonedcownamedRositaISAisthefirstintheworldthatincorporatestwohumangenesthatcontaintheproteinspresentinhumanmilksaidthestatement. TheArgentineteamsaidtheChineseonlyintroducedonehumangenewhiletheirresearchinvolvedtwomeaningthemilkwillmorecloselyresemblethatofhumans. Ourgoalwastoraisethenutritionvalueofcows'milkbyaddingtwohumangeneswhichdogoodtotheimmunesystemoftheinfants.saidAdrianMuttofromtheNationalUniversityofSanMartinwhichworkedwiththeinstitute. CristinaKirchnerPresidentofArgentinasaidthatthescientificinstitutemakesallArgentinesproud.Shealsorejectedthatshehadrejectedthehonourofhavingthecownamedafterher.TheycametotellmethatthenameisCristinabutwhatwomanwouldliketohaveacownamedafterher?ItappearedtometobemorepropertocallitRosita. 1WhydidthescientistsinArgentinaintroducetwohumangenesintotheclonedcow? A.BecausetheChineseengineersonlyintroducedonegeneintheirresearch. B.BecauseCristinaKirchnerPresidentofArgentinaexpectedthemtoincorporatetwogenes. C.Becausetwohumangenesenabledthecowtoproducemorenutritiousmilkfortheinfants. D.BecauseMuttofromtheNationalUniversityofSanMartinthoughttheycouldbethefirst toincorporatetwogenesinthecow. 2WhatcanbeinferredfromCristinaKirchner'sstatements? A.Shewasquitesatisfiedwiththeresearchdonebytheinstitute. B.Sheconsidereditanhonortonamethespecialcow. C.Shefeltitimpropertobenamedafterthecow. D.Sherefusedtogiveanametothecowoutofself﹣respect. 3WhichofthefollowingcanbestreplacetheunderlinedexpressioninParagraph4? A.havemorevarietiesthan B.bemoresimilarto C.havemorenutritionthan D.bemoredifferentfrom 4What'sthepassagemainlyabout? A.Theimportanceofgeneticengineering. B.Waystoimprovemother'smilk. C.Aclonedcowtoproducehuman﹣likemilk. D.AdvancedagriculturaltechnologyinArgentina.
“水培”是一种新型无土栽培其肥料是植物营养液下列营养液与草木灰草木灰显碱性混合使用后会降低肥效的是
“84”消毒液是生活中常见的物质主要用于杀菌消毒和漂白.如图为某厂家生产的“84”消毒液的商品标签 工业上一般用反应Cl2+2NaOH=NaCl+NaClO+H2O生产NaClO.请回答 1计算该消毒液NaClO中氯元素的质量分数结果保留0.1%. 2生产1吨该消毒液至少需要多少千克烧碱 3某同学将50g含NaClO5%的“84“消毒液稀释至1%需向原溶液中加入多少克水
分类法在学习和生活都具有非常重要的作用下列物质属于氧化物的是
Alexis17satquietlyinthepassengerseatofherdad'scar.Shelethereyeslazilyscanthelandscapeforwildlife.Thenadeercameintoviewabout200yardsinfrontofthem.Dadthere'sadeerthere!Alexissaid.Itwasamaledeerwithsharpantlers角oneachsideofitshead. AsthecarmovedcloserAlexissawthatthedeer'sheadwasbenttowardtheground.Thensheheardascreamandsawanarmflyupnearthedeer'shead.Alexisrealizedthedeerwasattackingawoman.Suea44﹣year﹣oldmotherhadbeenoutforhermorningrun.Thedeerfollowedherandedgedcloser.IknewIwasintroubleSuesays.Shewenttopickupastickforself﹣defenseandthedeercharged.Itliftedherwithitsantlersandthrewherintotheair.Suecouldfeelbloodflewdownherleg.Withinsecondsthedeerhadpushedherofftheroad. WhenAlexisandherfatherpulledupthedeerwasthrowingSuelikeadoll.Alexislookedintothewoman'sterrifiedeyesandbeforeherfatherhadevenstoppedthecartheteenagerjumpedquicklyoutofthecarandrantowardthedeer.Iwaskickingittogetitsattentionshesays.Thenherfatherwhohadfollowedhisdaughterpushedthedeerawayfromthewomen. AlexishelpedSueintothecarandthenappliedapieceofclothtoSue'sinjuredleg.We'regoingtogetyoutoahospitalAlexissaid.Thensheheardherfathershoutloudly.Hehadbeenknockedtotheground.Alexistookholdofahammerfromthecarandrantowhereherfatherlayonhisback.Shebeatthedeer'sheadandneckbuttheblowsdidn'tscareitaway.Iwaslosingfaithshesays.AcouplemorestrikesAlexissaidherfather.Youcandoit.TurningthehammeraroundAlexisclosedhereyesandbeatthedeer'sneckwithallherstrength.Whensheopenedhereyesthedeerwasrunningaway.Alexisgotinthedriver'sseatandspedtowardthenearesthospital. AfterSuewastreatedshetearfullythankedherrescuers.Youexpectateenagegirltogetonthephoneandcallforhelpshesaysnottobeatupadeer. 1WhatwasSuedoingwhenshewasattackedbythedeer? A.Shewasdrivinghome. B.Shewasrestingontheroad. C.Shewastakingexercise. D.Shewasfeedingwildanimals. 2WhatdidAlexisdotosaveSue? A.Shepushedthedeeraway. B.Shehitthedeerwithherfeet C.Shedrovethecartohitthedeer. D.Shebeatthedeerwithahammer. 3WhichofthefollowingwordscanbestdescribeAlexis? A.Strong. B.Cruel. C.Energetic. D.Brave. 4Whatisthebesttitleforthepassage? A.AWomanWasSeriouslyInjured B.ADangerousDeerAttackedaWoman C.AGirlRescuedHerFatherSuccessfully D.ATeenagerSavedOthersfromaDeerAttack
氢气是目前最清洁的燃料请根据氢气制备原理及性质回答下列问题 1对图1装置图仪器名称描述正确的是请填字母序号. A.①为酒精灯B.B为分液漏斗C.C为锥形瓶 2实验室制取并收集氢气所需的仪器是选填以上装置图编号. 3图2是检验氢气的部分装置请问装置G的作用如果气流中存在氢气在装置H中观察到的现象是产生该现象的原因是请用化学方程式解释该反应物中具有还原性的物质是填化学式.
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