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三棱锥P﹣ABC的高为PH，若三条侧棱相等，则H为△ABC的（ ）
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高一上学期数学《》真题及答案
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已知三棱锥S—ABC的三条侧棱两两垂直且SA=2SB=SC=4则该三棱锥的外接球的半径为
3
6
36
9
若三棱锥P﹣ABC的三条侧棱PAPBPC两两互相垂直且长都相等其外接球半径为2则三棱锥的表面积为．
正三棱锥P.―ABC的高为2侧棱与底面ABC成45o角则点A.到侧面PBC的距离为
正三棱锥S―ABC中若侧棱高SO=4则此正三棱锥S―ABC外接球的表面积是
36π
64π
144π
256π
已知三棱锥P﹣ABC中底面△ABC是边长为3的等边三角形侧棱长都相等．表面积为16π的球O过三棱锥
三棱锥P.﹣ABC三条侧棱两两垂直三个侧面面积分别为则该三棱锥的外接球表面积为
4π
6π
8π
10π
正三棱锥P.－ABC中三条侧棱两两垂直且侧棱长为则P.点到面ABC的距离是
九章算术中将底面为长方形且有一条侧棱与底面垂直的四棱锥称之为阳马将四个面都为直角三角形的三棱锥称之为
8π
12π
20π
24π
若三棱锥P﹣ABC的三条侧棱PAPBPC两两互相垂直且长都相等其外接球半径为2则三棱锥的表面积为．
在Rt△ABC中若∠C＝90°AC＝bBC＝a斜边AB上的高为h则有结论h2＝运用类比方法若三棱锥
在Rt△ABC中两直角边分别为ab设h为斜边上的高则=+由此类比三棱锥S﹣ABC中的三条侧棱SAS
九章算术中将底面为长方形且有一条侧棱与底面垂直的四棱锥称之为阳马将四个面都为直角三角形的三棱锥称之
12π
16π
20π
24π
已知正三棱锥S-ABC内接于半径为6的球过侧棱SA及球O.的平面截三棱锥及球面所得截面如下图则此三棱
一个三棱锥的各棱长均相等其内部有一个内切球即球与三棱锥的各面均相切球在三棱锥的内部且球与三棱锥的各面
@B.
@D.
已知三棱锥P﹣ABC的三条侧棱两两互相垂直且PA＝1PB＝1则此三棱锥外接球的体积为．
已知三棱锥S-ABC内接于半径为6的球过侧棱SA及球心O的平面截三棱锥及球面所得截面如右图则此三棱锥
正三棱锥S―ABC中若侧棱高SO=4则此正三棱锥S―ABC外接球的表面积是
36π
64π
144π
256π
在三棱锥O-ABC中三条棱OAOBOC两两互相垂直且OA＝OB＝OCM是AB的中点则OM与平面ABC
已知三棱锥P﹣ABC的三条侧棱PAPBPC两两互相垂直且PA＝PB＝PC＝a则该三棱锥的外接球的体
已知三棱锥P.﹣ABC的所有棱长都相等现沿PAPBPC三条侧棱剪开将其表面展开成一个平面图形若这个平
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10分英语课上老师要求同学相互修改作文.假设以下文章为你同桌所写请你对其进行修改.文章中共有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:在缺词处加一个漏词符号∧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. Alicewasnotontimeforschoolinthismorning.Shelookedlittletiredwhenshemetherchemistry'steacherMissGreen.Sheapologizedforherbeinglately.MissGreenaskedheriftherewassomethingwrongwithher.Thegirlsaidthathewasallrightsoshedidn'thavemuchsleeplastnight.Shewenttoafootballgameandtooksomepictures.Aftershegothomeshewasbusydevelopedthem.Shestayeduptillmidnight.MissGreentoldhertogetmoresleepatnight.Alicepromisesnottodothatagain.ThenAliceshowedMissGreenherbeautifulpicture.
30分RecentlyIpaidavisittoHarvardUniversitywheretherearetopclassscientistsandprofessorsandthebestacademicsystemintheworld. Iwasvery1whenIfirststeppedintothecampus校园.Wellit'snotevenreallyacampus.It's2likeanareainasmalltown.Harvard'smainbuildingsarefromthe18thcentury.Theylookveryoldand3.Youmight4saythey'realittleshabby破旧.Theydon'tfitthemodern5ofuniversityatall.Thebuildingsare6byflowersandtreessoIfeltasifIhadwalkedintoacastleoftheMid﹣Ages.ButwhenIlookedacrossthestreetthe7shopsandin﹣fashion时尚的studentsmademefeellikeIwasinthe21stcentury8.Itcreatesastrongcontrast对比andbringsaspecial9Ourtour10Garytookusaroundandtoldus.Youseethisgrassfieldinthecenteroftheschool?Hereiswheretheyholdtheir11ceremony仪式礼节.Theyjustsetuptentsandbenchesandhaveaverysimpleceremony.It's12!Whowouldthinkthemosttalentedstudentsjustgraduateonthegrass? I13somestudentsputablanketonthegrassandliedowntoreadabook.WhenIlistenedtothesoftsoundof14turningalongwiththesingingofthebirdsIfeltvery15.Therewasnocompetitivefeelingatall. Harvardhastheworld'sfirstcomputerinitssciencecentre16therearehundredsofhigh﹣endcomputerstoo.Itsreligionandtheliterature文学departmentsarealso17thebest.Itistheperfectmixoftraditionand18technology.ItmakesHarvardaveryattractiveplaceto19in. IhopeonedayI'll20mydreamschool﹣﹣﹣Harvard. 1.A.excited B.troubled C.shocked D.tired 2.A.more B.less C.little D.most 3.A.great B.solid C.noisy D.simple 4.A.still B.even C.ever D.yet 5.A.model B.way C.idea D.example 6.A.filled B.recovered C.surrounded D.floated 7.A.empty B.quiet C.free D.busy 8.A.once B.again C.only D.then 9.A.environment B.view C.atmosphere D.condition 10.A.guide B.partner C.visitor D.professor 11.A.celebration B.closing C.opening D.graduation 12.A.uninteresting B.unbelievable C.unbearable D.uncomfortable13.A.had B.saw C.felt D.imagined 14.A.books B.benches C.blankets D.pages 15.A.lucky B.calm C.nervous D.puzzled 16.A.but B.and C.though D.yet 17.A.among B.about C.to D.under 18.A.old B.new C.fast D.fresh 19.A.travel B.live C.study D.tour 20.A.serve B.visit C.find D.attend
下列有机物系统命名正确的是
如图反比例函数y＝x＞0的图象经过矩形OABC对角线的交点M分别交ABBC于点DE．若四边形ODBE的面积为12则k的值为．
如图在菱形ABCD中已知AB＝4∠ABC＝60°∠EAF＝60°点E在CB的延长线上点F在DC的延长线上有下列结论①BE＝CF②∠EAB＝∠CEF③△ABE∽△EFC④若∠BAE＝15°则点F到BC的距离为2﹣2．则其中正确结论的个数是
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. WhennewscamethatIwasnotchosenasthememberofthevolleyballteamIwassuchfrustratedthatIalmostdecidedtogiveup.HowevermybestfriendMirandaanalyzedmyproblemspointedoutthatmylazinessandpoorpreparationledmyfailure.FromthenonIdevotedallmysparetimetopracticeplayingandconsultinghisteachersaboutskillseveryday.WhenanotherchancecameIhadgotfullyprepared.AsaresultofIwasselectedandbecameoneofthemostimportantplayerinourschoolteam.FromthisstoryIamdefiniteconvincedthatthebetterpreparedwearethemuchlikelyweareabletoachieveourgoals.
如图⊙O的直径AB垂直于弦CD垂足是点E∠CAO＝22.5°OC＝6则CD的长为
设ab是方程x2+x﹣2019＝0的两个实数根则a﹣1b﹣1的值为．
10分 Flavoring Mostdrinksstatingthattheyarefruit﹣flavored水果味道的containnofruitatallwhilemostoftherestcontainonlyasmallquantityoffruitaccordingtoastudycarriedbytheBritishFoodCommission. Shoppersneedtocheckthelabels标签beforebuyingdrinksthoughsometimestheactualcontentcanbenon﹣existentsaidFoodCommissionspokespersonIanTokelove.Foodproductionishighlycompetitive.1Itwillincreaseprofitsandconsumerswon'talwaysrealizetheyarebeingtricked. Flavoringsarefocusedontheflavorsofnaturalfoodproductssuchasfruitsmeatsandvegetablesorcreatingflavorforfoodproductsthatdonothavethedesiredflavors.Researchersanalyzedthecontentsof28strawberry﹣flavoredproductssoldinstores.2Ofthe11productsthatdidcontainstrawberriesfiveofthemcontainedlessthanonepercentrealfruit.Inadditioneachjuiceboxcontainednearlyeightteaspoonsofsugar. 3Let'stakejamasanexample.Somestrawberry﹣flavoredjamwaslabeledascontainingnoartificialcolorsflavorsorsweetenersbutitcontainedabsolutelynostrawberriesatall. 4Consumershavetherightstoknowclearlyaboutwhattheyhavebought.UndercurrentUKlawfoodpackagesdonothavetodistinguishbetweennaturalandartificialflavoring.Describingaproductasstrawberryflavorandcoveringthesurfaceofthepacketwithpicturesofstrawberriesismisleading.5UnfortunatelyitisalsolegalandwidespreadTokelovesaid.It'stimetotakemeasurestoprotecttheconsumers'rights. A.Theproductswhichcontainrealfruitarepopularwithpeople. B.Evenproductsadvertisedasmorenaturaloftencontainednofruit. C.Theyfoundthatabout60vpercentofthemdidn'tcontainanyfruitatall. D.Ifcompaniescancuttheircostsbyusingflavoringtheyarelikelytodoso. E.Itisimportantandneessarytodemandasmallamountofflavoringintheproducts. F.Actuallytheproductcontainsjustatinypercentageofstrawberryorevennofruitatall. G.TheFoodCommissionsuggestedallflavorsusedinaproductshouldbelistedonthepackaging. 1. 2. 3. 4. 5.
如图1在平面直角坐标系中抛物线y＝﹣x2+bx+c经过点A﹣50和点B10． 1求抛物线的解析式及顶点D的坐标 2点P是抛物线上AD之间的一点过点P作PE⊥x轴于点EPG⊥y轴交抛物线于点G过点G作GF⊥x轴于点F当矩形PEFG的周长最大时求点P的横坐标 3如图2连接ADBD点M在线段AB上不与AB重合作∠DMN＝∠DBAMN交线段AD于点N是否存在这样点M使得△DMN为等腰三角形若存在求出AN的长若不存在请说明理由．
如图在Rt△ABC中∠B＝90°AB＝5BC＝12将△ABC绕点A逆时针旋转得到△ADE使得点D落在AC上则tan∠ECD的值为．
8分Howfarwouldyoubewillingtogotosatisfyyourneedtoknow?Farenoughtofindoutyourpossibilityofdyingfromaterribledisease?Thesedaysthat'smorethananacademicquestionasTracySmithreportsinourCoverStory. Therearenowmorethanathousandgenetic基因的testsforeverythingfrombaldnesstobreastcancerandthelistisgrowing.Questionisdoyoureallywanttoknowwhatmighteventuallykillyou?ForinstanceNobelPrize﹣winningscientistJamesWatsononeofthefirstpeopletomaptheirentiregeneticmakeupissaidtohaveaskednottobetoldifhewereatahigherriskforAlzheimer老年痴呆症. IfItellyouthatyouhaveanincreasedriskofgettingaterriblediseasethatcouldweighonyourmindandmakeyouanxiousthroughwhichyouseetherestofyourlifeasyouwaitforthatdiseasetohityou.ItcouldreallymessyouupsaidDr.RobertGreenaHarvardgeneticist. EveryacheandpainSmithsuggestedcouldbeunderstoodasthebeginningoftheend.That'sright.IfyoueverworriedyouwereatriskforAlzheimer'sdiseasetheneverytimeyoucan'tfindyourcarintheparkinglotyouthinkthediseasehasstarted. Dr.Greenhasbeenthinkingaboutthisissueforyears.HeledastudyofpeoplewhowantedtoknowiftheywereatahighergeneticriskforAlzheimer's.Itwasthoughtthatpeoplewhogotbadnewswouldforlackofabettermedicaltermfreakout.ButGreenandhisteamfoundthattherewasnosignificantdifferencebetweenhowpeoplehandledgoodnewsandpossiblytheworstnewsoftheirlives.Infactmostpeoplethinktheycanhandleit.PeoplewhoaskfortheinformationusuallycanhandletheinformationgoodorbadsaidGreen. 1.Thefirstparagraphismeantto. A.asksomequestions B.introducethetopic C.satisfyreaders'curiosity D.describeanacademicfact 2.WhichofthefollowingistrueofJamesWatson? A.Heisstronglyinfavorofthepresentgenetictests. B.HeismorelikelytosufferfromAlzheimer'sdisease. C.Hebelievesgeneticmappingcanhelpcureanydisease. D.Hedoesn'twanttoknowhischanceofgettingadisease. 3.TheunderlinedpartfreakoutinParagraph5isclosestinmeaningto. A.breakdown B.dropout C.leaveoff D.turnaway 4.ThestudyledbyDr.Greenindicatesthatpeople. A.prefertoheargoodnews B.tendtofindoutthetruth C.canacceptsomebadnews D.havetherighttobeinformed
30分AtfirstpeopleintheUSthoughtEbola埃博拉wasonlyadiseaseaccompaniedwithfeverandfoundinAfricaatthebeginning.1thenamanfromwestAfricadiedfromEbolaatahospitalinDallasTexas.Andtwonurses2forhimbecameinfected感染withtheviruswhichmadetheUSgovernmentpublishnewguidelinesto3healthworkers. TopAmerican4haverepeatedlysaidthatmostpeoplehavelittlechanceofbeinginfected.Expertshave5thatEbolacanonlybespreadthroughinfectedperson'sbodyfluids﹣likeblood.Butit6thatmanyAmericansare7whattheyhaveheard. Arecentsurveyfoundmorethan80percentofAmericansbelievethatEbolacanbespreadinmany8includingairforcedthroughthenoseormouth.BesidestheHarvardSchoolofPublicHealth9thefindings.Thestudyalsoshowedthatmostadultsfeartherewillbean10ofEbolaintheUnitedStatessoon.11surveyfoundthatmorethan70percentofAmericanswouldsupportcallsto12traveltoandfromEbola﹣affectedpartsofAfrica. ThomasFriedenheadstheU.S.CentersforDiseaseControlandPrevention.Whenaskedwhether 13officialshadconsideredatravelbanMr.Friedenhad14tosay:Wewon'tbeabletochecktravelersfor15whentheyleaveorwhentheyarrive.Wewon'tbeableaswedo16totakeadetailedhistorytoseeiftheywere17whentheyarrive.Whenthey18wewouldn'tbeabletoimposequarantine强加隔离aswenowcaniftheyhavehigh﹣risktouch. LastweekPresidentBarackObamaurgedAmericansnotto19whathecalledpanicorfear.ThisweektheadministrationannouncedthatalltravelersreachingtheUnitedStatesfromsomeAfricannationsare20topassthroughoneoffiveairports. 1.A.Just B.Yet C.So D.Even 2.A.arranging B.caring C.searching D.standing 3.A.treat B.attend C.inspec tD.protect 4.A.policemen B.officers C.physicists D.doctors 5.A.stated B.suggested C.considered D.regretted 6.A.proves B.happens C.says D.appears 7.A.studying B.discussing C.questioning D.determining 8.A.ways B.areas C.organs D.countries 9.A.announced B.received C.realized D.rejected 10.A.increase B.income C.decrease D.outbreak 11.A.Theother B.Another C.Thesame D.One 12.A.forbid B.expect C.require D.allow 13.A.foreign B.royal C.African D.federal 14.A.that B.this C.nothing D.those 15.A.change B.money C.fever D.crime 16.A.immediately B.previously C.presently D.regularly 17.A.examined B.searched C.explored D.exposed 18.A.leave B.arrive C.live D.stay 19.A.lookforwardto B.payattentionto C.giveinto D.addupto 20.A.persuaded B.required C.advised D.guided
在我市“青山绿水”行动中某社区计划对面积为3600m2的区域进行绿化经投标由甲乙两个工程队来完成．已知甲队每天能完成绿化的面积是乙队每天能完成绿化面积的2倍如果两队各自独立完成面积为600m2区域的绿化时甲队比乙队少用6天． 1求甲乙两工程队每天各能完成多少面积的绿化 2若甲队每天绿化费用是1.2万元乙队每天绿化费用为0.5万元社区要使这次绿化的总费用不超过40万元则至少应安排乙工程队绿化多少天
如图在岷江的右岸边有一高楼AB左岸边有一坡度i＝12的山坡CF点C与点B在同一水平面上CF与AB在同一平面内．某数学兴趣小组为了测量楼AB的高度在坡底C处测得楼顶A的仰角为45°然后沿坡面CF上行了20米到达点D处此时在D处测得楼顶A的仰角为30°求楼AB的高度．
8分Aslifeexpectancyincreasesnowadaystheaveragepersonliveswellbeyondtheageofretirement.Asaresulttheelderlymakeupanever﹣increasingpercentageofsocietywhichmakesitmoreimportantthaneverforarealefforttobemadeinimprovingthelivesofseniorcitizens. Onewaytodealwiththesituationwouldbetoensurethattheelderlyhaveenoughmoneyonwhichtolive.Obviouslywhenapersonstopsworkingtheystillrequireasourceofincometocovertheirbasicneedssuchasfoodaccommodationandheating.Aclearsolutiontotheproblemisforthegovernmenttomakesurethatthestatepensionisadequatefortheseneeds. Stepsshouldalsobetakentoovercomethehealthproblemstheelderlyface.Thegovernmentshouldalsoprovideaccesstothebesthealthcareavailablewhichmaynecessitatepayingforresidentialhomeswheretheelderlycanhaveround﹣the﹣clocknursingorattheveryleastprovidingmedicationfreeofchargetoallpeopleoveracertainage. Thelivesofoldpeoplecouldbeimprovedifattemptsweremadetoaddresstheproblemofsocialisolation.Ifweorganisedtripsfortheelderlytocommunitycentresvisitsfromsocialworkerstheirproblemoflonelinesscanbereducedalotwhichmarksthelivesofsomanyoldpeoplelivingaloneandfarfromtheirfamilies. Onefinalsuggestionwhichwouldhelpenormouslyistochangetheattitudeofthecommunitytowardsitsoldermemberswhoarealltoooftenseenasaburdenonsocietyanddismissedashavinglittletodowithmodernlife.Weneedtobetaughtfromanearlyagetorespecttheviewsofoldpeopleandappreciatetheirbroaderexperienceoflife.Thiswouldhelpsocietyasawholeandencourageappreciationoftherolethatoldpeoplecanstillplaytoday. 1.Whatdoesthepassagemainlytalkabout? A.Alltheelderlycanenjoyfreemedication. B.Thenursescantakegoodcareoftheelderly. C.Somesuggestionswouldbemadetoimprovethelivesoftheelderly. D.Thehealthcareavailabletotheelderlyisgood. 2.TheunderlinedwordaddressinParagraph4probablymeans. A.findout B.dealwith C.putdown D.pickup 3.Whatfactorsaffectedtheoldpeople'slife? a.thestatepension b.thebasicneeds c.theattitudeofthecommunity d.theexperienceoflife e.socialisolation f.medicalcare A.abcd B.bcde C.cdef D.acef 4.Accordingtothelastsuggestiontheoldpeople. A.shouldberespectedbyallofus B.havetogathermorelifeexperience C.mayberegardedasourheavyburden D.mustchangetheirattitudetothecommunity
6分EachmorningGrandpawasupearlysittingatthekitchentablereadinghisbook.Hisgrandsonwantedtobejustlikehimandtriedtocopyhimineverywayhecould.OnedaythegrandsonaskedGrandpaItrytoreadthebookjustlikeyoubutIdon'tunderstanditandIforgetwhatIunderstandassoonasIclosethebook.Whatgooddoesreadingthebookdo? ThegrandpaquietlyturnedfromputtingcoalinthestoveandrepliedTakethiscoalbasketdowntotheriverandbringmebackabasketofwater.Theboydidashewastoldbutallthewaterleakedoutbeforehegotbacktothehouse.ThegrandpalaughedandsaidYou'llhavetomovealittlefasternexttimeandsenthimbacktotheriverwiththebaskettotryagain. Thistimetheboyranfasterbutagainthebasketwasemptybeforehereturned.Outofbreathhetoldhisgrandpathatitwasimpossibletocarrywaterinabasketsohewenttogetabucketinstead.ThegrandpasaidIdon'twantabucketofwater;Iwantabasketofwater.You'rejustnottryinghardenough. Theboyagaindippedthebasketintotheriverandranhardbutwhenhereachedhisgrandpathebasketwasemptyagain.OutofbreathhesaidGrandpait'suseless!Soyouthinkitisuseless?thegrandpasaidLookatthebasket. Theboylookedatthebasketandforthefirsttimeherealizedthatthebasketwasdifferent.Ithadbeentransformedfromadirtyoldcoalbasketandwasnowclean.Grandsonthat'swhathappenswhenyoureadthebook.Youmightnotunderstandorremembereverythingbutwhenyoureadityou'llbechangedinsideandout. 1.Whatpuzzledthegrandsonmostwas. A.whetheritwasusefultoreadbooks B.whyheforgotwhathereadsoon C.whatkindofbookhecouldunderstand D.howhecouldreadbookslikehisgrandpa 2.WhydidGrandpaaskhisgrandsontofetchabasketofwater? A.Totrainhimtorunfaster. B.Tocleanthedirtybasketintheriver. C.Topunishhimfornotreadingcarefully. D.Togethimtorealizetheuseofreadingbooks. 3.Whatlessoncanwelearnfromthestory? A.Theoldarealwayswiserthantheyoung. B.Itisfoolishtocarrywaterwithabasket. C.Readingbookscanchangeapersongradually. D.Youcan'texpecttorememberwhateveryouread.
PM2.5是指大气中直径小于或等于2.5微米的颗粒物也叫可入肺颗粒物与肺癌哮喘等疾病的发生密切相关是灰霾天气的主要原因．它主要来自化石燃料的燃烧如机动车尾气燃煤等．下列与PM2.5相关的说法不正确的是
10分Justlikechildrenbabyanimalsspendcountlesshoursatplay.Afterstudyinganimalplayformanyyearsscientistsrecognizethatyounganimalplayispracticeforadultbehavior.Todaythisplayisroughlydividedintothefollowinggroups. Locomotorplayreferstothemovementsanimalscarryoutintheirplay.Runningleapingturningandkickingaresomeofthemostcommonexamplesoflocomotorplay.Anadultdeermayrunleapandtwisttoescapeitsattackers.Playmovementslikethesesurelymakeyounganimalsnimble.Somedaytheseskillsmighthelpsavetheirlives. Movingforwardslowlyattackingsuddenlyandbitingareexamplesofpredatoryplaythathelpyoungpredatorsprepareforalifeofrunningafterandtakingholdofotheranimals.Wildcatswolvesandbearsarepredators.Itisverycommontoseetheseyounganimalsplaythiskindofgameswhichsharpentheirskillsandteachthemabouttheirstrengthsandlimitations. Forchildrenplayingwithtoysisbothfunandeducational.Ithelpsimprovetheirhandandeyemovementsaswellasdevelophandskillstoaccomplishtasks.Itisthesamewithanimals.Youngchimpanzeesimprovetheirhandskillswhileplayingwithsticks.Birdsalsoplaywiththingsinwaysthatteach.Swallowsdropandrecoverfeathersinmidair.Divingsuddenlytocatchthefeathersisagoodpracticeforcatchingflyinginsects. Socialplayhelpsanimalslearnhowtobehavewhentheyrunintootheranimals.Anditteachesanimalsaboutcommunication.Ananimalgivessignalstoletanotheranimalknowitwantstoplay.Manyanimalsgivesignalsbyshowingaplayface.Insomewaysthisfaceislikeahumansmile;theanimalholdsitsmouthinarelaxedandopenmanner.Duringplay﹣fightssomeanimalsmaystepbackwardstosignalthattheyareplayingandnotactingseriously. Untilnowscientistshaveunderstoodplayfulactshelpprepareanimalsfortheirseriousadultsituations.Butthenumbersofplayfulspeciesandexamplesofanimalplayarevast.Thepurposeofanimalplaymayhavemeaningsscientistshavenotdiscoveredyet. 1.Themainpurposeofthetextisto. A.askustotakegoodcareofwildanimals B.encourageustolearnmoreaboutanimals C.entertainuswithinterestinganimalstories D.showussomethingaboutanimalbehavior 2.TheunderlinedwordnimbleinParagraph2canbestbereplacedby. A.cruel B.swift C.curious D.strong 3.Whichofthefollowingbelongstopredatoryplay? A.Adeerrunsleapsandturns. B.Achimpanzeeplayswithastick. C.Alionmovesslowlyandmakesanattacksuddenly. D.Adogholdsitsmouthinarelaxedandopenmanner. 4.BasedonParagraph5aplayfaceis. A.atypeofsignalbetweenanimals B.anameforakindofanimalplay C.anactivitythatinvolvesadultanimals D.anactionthatistaughttoanotheranimal 5.Whichofthefollowingshowsthestructureofthetext?
下列分离或提纯物质的方法正确的是
下列运算正确的是
15分Agroupoffrogsweretravelingthroughthewoodsandtwoofthem1fallintoahole.Alltheotherfrogslookeddown.Whentheysawhowdeep2holewastheytoldthetwofrogsthattheywoulddiesoon. Atfirstbothofthetwofrogsdidn'tcaretheirwordsandtried3besttojumpoutofthehole.Theotherfrogskepttellingthemtostopbecausetheythoughttherewasnochance4jumpoutofsuchadeephole.Finallyoneofthetwofrogsbelievedthesewordsandgaveup.Hefelldownanddied. Theotherfrogcontinuedtojumpashardashecould.Onceagainthecrowdoffrogsshoutedathimtostopthepainandjustdie.Hejumpedeven5hardandfinallysucceeded.WhenhegotouttheotherfrogsaskedDidn'tyouhearus?6theirgreatsurprisethefrogturnedouttobedeaf.Hethoughttheywerehelpinghimallthetimenot7stophim. Thisstoryteachestwolessons:Thereispoweroflifeanddeathinthetongue.Well﹣meantwordscanhelppeopleintrouble.Butevilwordssometimescankillthem.Becarefulof8yousay. Rememberthepowerofwords.Anyonecanspeakwords9arelikelytomakepeoplegiveupindifficult10time. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
设NA表示阿伏加德罗常数下列叙述中正确的是
6分Noonewouldmuchliketheideaofeating61poundsoftomatoesaday.Butiftheirgoodnesswasputintoaneasy﹣to﹣swallowpillthatyouweretoldmightpreventstrokes中风andheartattacksyouwouldprobablybeputtinginanordertomorrow. Researchersbelievetheymayhavecomeupwithjustthataftertrials.Thedailypillcontainsachemicalcalledlycopenewhichmakestomatoesredandisknowntobreakdownfatinthevessels血管.ACambridgeUniversitystudyfoundtakingthepillsimprovedbloodflowandtheliningofvesselsinpatientswithpre﹣existingheartconditions.Italsoincreasedtheflexibilityoftheirvesselsby50percent.Thescientistsbelieveitcouldlimitthedamagecausedbyheartdisease﹣responsiblefor180000deathsayear﹣andhelpcutthe49000deathsayearfromstrokes.Theyalsohopeitcouldbenefitthosewitharthritis关节炎diabetes糖尿病andevenslowtheprogressofcancer. Eachpillisequaltoeatingaround61poundsofripetomatoes.StudieshaveshowneatingaMediterranean﹣styledietrichintomatoesfishvegetablesnutsandoliveoilcansignificantlyreducecholesterol胆固醇andhelppreventcardiovasculardisease. Preliminaryresultsfromatwo﹣monthtrialinwhichthepillwasgivento36heartdiseasepatientsand36healthyvolunteerswithanaverageageof67werepresentedatameetingoftheAmericanHeartAssociation.Itwasshowntoimprovethefunctionoftheendothelium﹣thelayerofcellsliningbloodvessels.Italsoimprovedtheirsensitivitytonitricoxidethegaswhichcausestheenlargementofthevesselsinresponsetoexercise. IanWilkinsonheadofCambridgeUniversity'sclinicaltrialsunitsaidTheseresultsarepotentiallyverysignificantanditmeetsthegoalbutweneedmoretrialstoseeiftheytranslateintofewerheartattacksandstrokes. Furtherstudiesareplannedwithresearchershopingitcouldofferachoiceforheartdiseasesuffererswhocannottakethecholesterol﹣lowingdrugs. MikeKnaptonheadoftheBritishHeartFoundationsaidAlthoughthisshowedlycopeneimprovedbloodflowinpeoplewithheartdiseasethat'salongwayfromdemonstratingthattakingitcouldimproveoutcomesforpeoplewithheartdisease.Thebestwaytogetthebenefitsofagooddietistoeatplentyoffreshfruitandvegetables. 1.WhatcanweinferfromParagraph1? A.Wecaneattoomuchtomatofood. B.Tomatoesarehelpfultostrokesandheartattacks. C.Tomatoeswilllosehealthyelementswereputintopills. D.Wehadbetternoteattomatoes. 2.Wecanlearnfromthepassagethatthepills. A.areattheexperimentstage B.cancureallthedisease C.arewidelyusedamongpatients D.costpatientssolittlemoney 3.WhatWasIanWilkinson'sopiniononthetrial? A.Disappointing. B.Surprising. C.Satisfactory. D.Terrible.
下列关于合成材料的说法中不正确的是
6分NingZetaohasbecomeChina'snewswimmingstarduetohisamazingperformanceatthe2014AsianGamesinIncheon仁川SouthKorea.Withalreadytwogoldmedalsinhandthe21﹣year﹣oldclocked47.70secondsinthe100mfreestylesettinganewAsianrecord.ThisresulthasbeenrecognizedbyFINAastheworld'sthirdbesttimethisyearfastenoughtohavewonagoldmedalinlastyear'sBarcelonaWorldChampionships.ItismyfirstinternationaleventsaidNingwholaterwonafourthgoldmedalinIncheon.Iamhappythatmyresultsareprettyclosetomypersonalbest. BorninthecentralChinesecityofZhengzhouNingenteredthelocalteamattheageof11andjoinedthenavyteamin2007.Hefirstcaughtpeople'sattentionin2009whenhefinishedeighthinthe200mindividualmedley混合泳attheNationalGames. NeverthelessNingsufferedfromboneinfectioninbothkneesforalongtimewhichmadehimunabletotrainhardonhiskicks.Healsohadanindigestionproblemandhadtoeatsoftfoodwhichiseasytodigest.Hispoorstomachevenmadeitimpossibleforhimtocompleteweek﹣longfulltimetraining.Buttheyoungswimmernevergivesup.HisidolisthegreatRussianswimmerAlexanderPopovwhocontinuedtowinOlympicgoldmedalsafterhewasstabbed刺伤onastreet.NingsaidHewasarealfighterandIneedtolearnfromhim. TakenbettercareofbycoachesanddoctorsNingcannowtrainasnormallyasothers.Andthatiswhyhecangettoday'sachievements.ThegoldmedalsattheAsianGamesalsoboostedtheconfidenceofthenewswimmingstarwhohopestoenterthenationalteamandcompeteforChinainmoreinternationalevents.Chinesemaleswimmershaveneverbeenplacedamongtopeightintheshort﹣distancefreestylehesaid.IhopeIcandoitjustlikewhatSunYangdidinthemid﹣longdistancefreestyle. 1.Thebesttitlecouldbe. A.NingZetaoaworldfamousswimmer B.NingZetaoapromisingrisingstar C.NingZetaoastrong﹣willedsoldier D.NingZetaoaworldgoldmedalist 2.Wecanlearnfromthepassagethat. A.theresultsNinggotinIncheonarehisbest B.Ningisgoodatboth100mand200mfreestyle C.NingbrokeanAsianrecordatthe2014AsianGames D.Ninghasalreadygot5goldmedalsintheinternationalevent 3.Itcanbeinferredfromthepassagethat. A.somehealthproblemshavelittleeffectonNing'straining B.beingwellcaredofisthemainreasonforNing'sachievements C.theChineseswimmershavenevergotintothetopeighthintheworldevent D.goldmedalistasNingisheisnotyetamemberofNationalSwimmingTeam
函数y＝中自变量x的取值范围是
25分假定你是希望中学学生李华得知2017年香港大学要在大陆进行自主招生的消息后有意向香港大学申请参加自主招生考试请用英语写一封自荐信主要包括:1.个人信息2.性格爱好与特长3.学习情况注意:1.词数100左右;2.信的开头已为你写好不计入总词数;3.可根据内容要点适当增加细节以使行文连贯.4.参考词汇:自主招生independentrecruitmentDearSirMynameisLiHuafromHopeHighSchool.YoursLiHua.
某班七个兴趣小组人数如下566x789已知这组数据的平均数是7则这组数据的中位数是
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