首页
试卷库
试题库
当前位置：
X题卡
>
所有题目
>
题目详情
已知抛物线C：y2＝2px（p＞0）的焦点为F，准线为l，过焦点F的直线分别交准线l于点A，交抛物线C于点B，且，则|AB|＝（ ）
查看本题答案
包含此试题的试卷
高三下学期数学《》真题及答案
点击查看
你可能感兴趣的试题
如图在平面直角坐标系xOy中已知直线lx-y-2=0抛物线C://y2=2pxp＞0. 1若直线l
已知抛物线y＝2px2p＞0的焦点为F.点P.1在抛物线上过P.作PQ垂直抛物线的准线垂足为Q.若抛
设抛物线y2＝2pxp＞0的焦点为F.点A.02.若线段FA的中点B.在抛物线上则B.到该抛物线准线
已知抛物线y2=2px以过焦点的弦为直径的圆与抛物线准线的位置关系是.
如图过抛物线y2＝2pxp>0的焦点F.的直线l交抛物线于点A.B.交其准线于点C.若|BC|＝2|
若抛物线y2＝2px的焦点坐标为10则p＝________准线方程为________.
若抛物线y2=2px的焦点坐标为10则p=;准线方程为.
已知抛物线C.y2＝2pxp>0P－10是抛物线C.的准线与x轴的交点过P.的直线l与抛物线C.交于
已知抛物线y2＝2pxp>0过其焦点且斜率为1的直线交抛物线于A.B.两点若线段AB的中点的纵坐标为
设抛物线y2=2pxp＞0的焦点为F点A02若线段FA的中点B在抛物线上则B到抛物线准线的距离为．
已知抛物线y2=2pxp>0的准线经过点-11那么抛物线的焦点坐标为.
已知抛物线y2＝2pxp＞0过其焦点且斜率为1的直线交抛物线于
，
两点，若线段AB的中点的纵坐标为2，则该抛物线的准线方程为( ) A.x＝1B.x＝－1
x＝2
x＝－2
已知抛物线C://y2=2pxp＞0的焦点为F直线y=4与y轴的交点为P与C的交点为Q且 求
设抛物线y2=2pxp＞0的焦点为F已知AB为抛物线上的两个动点且满足∠AFB=60°过弦AB的中点
已知点A.02抛物线y2=2pxp>0的焦点为F.准线为l线段FA交抛物线于点B.过点B.作l的垂线
已知抛物线y2=2pxp>0的准线与圆x2+y2-6x-7=0相切则p=.
已知抛物线y2＝2pxp>0的准线经过点－11则该抛物线焦点坐标为
(－1,0)
(1,0)
(0，－1)
(0,1)
在直角坐标系xOy中有一定点A.21若线段OA的垂直平分线过抛物线y2=2pxp>0的焦点则该抛物线
已知抛物线y2=2pxp>0过其焦点且斜率为1的直线交抛物线于
B.两点,若线段AB的中点的纵坐标为2,则该抛物线的准线方程为( ) A.x=1
x=-1
x=2
x=-2
已知抛物线y2＝2pxp＞0过其焦点且斜率为1的直线交抛物线于A.B.两点若线段AB的中点的纵坐标为
热门试题
更多
假定你是李华暑假在伦敦学习得知当地美术馆要举办中国画展.请写一封信申请做志愿者内容包括: 1.写信目的; 2.个人优势; 3.能做的事情. 注意: 1.词数100左右; 2.可以适当增加细节以使行文连贯; 3.结束语已为你写好.
﹣Iwillhavetwofinalexamstomorrow. ﹣Metoo.Soyouanysympathyfrommehere. A.aren'tgetting B.didn'tget C.hadn'tgot D.haven'tgot
已知函数fx＝ex﹣ax﹣1gx＝lnx﹣ax+a若对x∈[1e]均有fx•gx≤0则实数a的最小值为
Cooperationatworkisgenerallyseenasagoodthing.ThelatestsurveybytheFinancialTimesofwhatemployerswantfromMBAgraduatesfoundthattheabilitytoworkwithawidevarietyofpeoplewaswhatmanagerswantedmost.Butmanagersalwayshavetobalancethebenefitsofteamworkwhichhelpensurethateveryoneisworkingtowardsthesamegoalwiththedangersof'groupthink'whencriticsarereluctanttopointoutaplan'sdrawbacksforfearofbeingkeptoutofthegroup.ThedisastrousBayofPigsinvasionofCubain1961wasaclassiccaseofgroupthink.SkepticswerereluctanttochallengeJohnF.KennedythenewlyelectedAmericanpresident.Moderncommunicationmethodsmeanthatcooperationismorefrequent.Workersareconstantlyintouchwitheachotherviaemailmessaginggroupsormobilecalls.Butdoesthatimproveorlowerperformance?AnewstudybythreeAmericanacademicstriedtoanswerthisquestion.Theysetalogicalproblemdesigningtheshortestrouteforatravellingsalesmanvisitingvariouscities.Threegroupswereinvolved:onewheresubjectsactedindependently;anotherwheretheysawthesolutionspostedbyteammembersateverystage;andathirdwheretheywerekeptinformedofeachother'sviewsonlyintermittently.Thesurveyfoundthatmembersoftheindividualistgroupreachedthepremiersolutionmoreoftenthantheconstantcooperatorsbuthadapooreraverageresult.Theintermittentcooperatorsfoundtherightresultasoftenastheindividualistsandgotabetteraveragesolution.Whenitcomestoidealgenerationgivingpeopleabitofspacetoasolutionseemstobeagoodidea.Occasionalcooperationcanbeabighelp:mostpeoplehavebenefitedfromacolleague'sbrainwaveorjustasoftenwiseadvicetoavoidaparticularcourseofaction.FurthercluescomefromabookSupermindsbyThomasMaloneoftheMassachusettsInstituteofTechnology.Hesaysthatthreefactorsdeterminethecollectiveintelligenceofcooperatinggroups:socialintelligencehowgoodpeoplewereatratingtheemotionalstatesofothers;theextenttowhichmemberstookpartequallyinconversationthemoreequalthebetter;andthecooperationofwomeninthegroupthehigherthebetter.Groupsrankedhighlyintheseareascooperatedfarbetterthanothers.Inshortcooperationmaybeausefultoolbutitdoesn'tworkineverysituation.1TheauthorcitestheexampleofTheBayofPigsinvasionofCubainParagraph1to.A.provethatteamplayersareskilledatcommunicationB.showthatteamworkcannotalwaysbebeneficialC.provethatcriticsareunwillingtochallengeanybodyD.showthedangerofgroupthinkisnotveryserious2Theunderlinedphrase'theintermittentcooperators'inParagraph3refersto.A.thosewhodonotcooperatewitheachotherB.thosewhoareseldominformedofother'sviewsC.thosewhocooperatewithothersoccasionallyD.theconstantcooperatorswithapooraverageresult3Whichofthefollowingfactorsmakesateamcooperatebetteraccordingtothefourthparagraph?A.Groupmemberscooperatingallthetime.B.Groupmembersinagoodemotionalstate.C.Equaldistributionofmenandwomen.D.Equalparticipationinthecommunication.4Whichcanbethebesttitleofthepassage?A.WhenTeamworkWorksB.WhatTeamworkIsAboutC.WhyTeamworkOperatesD.AUsefulTool:Cooperation
Itwasnearlyaweektherescueteamlocatedthecrashedplane. A.since B.before C.until D.after
Studentsshouldinvolvethemselvesincommunityactivitiestheycangainexperienceforgrowth. A.who B.when C.which D.where
IfshemakesuchasimplewishasnottobeteasedfordisabilitylastChristmasAmywouldstillfeellonelynow. A.haddarednot B.hadn'tdaredto C.darednot D.didn'tdareto
Asdataandidentitytheftbecomesmoreandmorecommonthemarketisgrowingforbiometric生物测量technologies﹣likefingerprintscans﹣tokeepothersoutofprivatee﹣spaces.Atpresentthesetechnologiesarestillexpensivethough.ResearchersfromGeorgiaTechsaythattheyhavecomeupwithalow﹣costdevice装置thatgetsaroundthisproblem:asmartkeyboard.Thissmartkeyboardpreciselymeasuresthecadence节奏withwhichonetypesandthepressurefingersapplytoeachkey.Thekeyboardcouldofferastronglayerofsecuritybyanalyzingthingsliketheforceofauser'stypingandthetimebetweenkeypresses.Thesepatternsareuniquetoeachperson.Thusthekeyboardcandeterminepeople'sidentitiesandbyextensionwhethertheyshouldbegivenaccesstothecomputerit'sconnectedto﹣regardlessofwhethersomeonegetsthepasswordright.Italsodoesn'trequireanewtypeoftechnologythatpeoplearen'talreadyfamiliarwith.Everybodyusesakeyboardandeverybodytypesdifferently.Inastudydescribingthetechnologytheresearchershad100volunteerstypetheword'touch'fourtimesusingthesmartkeyboard.Datacollectedfromthedevicecouldbeusedtorecognizedifferentparticipantsbasedonhowtheytypedwithverylowerrorrates.Theresearcherssaythatthekeyboardshouldbeprettystraightforwardtocommercializeandismostlymadeofinexpensiveplastic﹣likeparts.Theteamhopestomakeittomarketinthenearfuture.1Whydotheresearchersdevelopthesmartkeyboard?A.Toreducepressureonkeys.B.Toimproveaccuracyintyping.C.Toreplacethepasswordsystem.D.Tocutthecostofe﹣spaceprotection.2Whatmakestheinventionofthesmartkeyboardpossible?A.Computersaremucheasiertooperate.B.Fingerprintscanningtechniquesdevelopfast.C.Typingpatternsvaryfrompersontoperson.D.Datasecuritymeasuresareguaranteed.3Whatdotheresearchersexpectofthesmartkeyboard?A.It'llbeenvironment﹣friendly.B.It'llreachconsumerssoon.C.It'llbemadeofplastics.D.It'llhelpspeeduptyping.4Whereisthistextmostlikelyfrom?A.Adiary.B.Aguidebook.C.Anovel.D.Amagazine.
如图在四棱锥P﹣ABCD中AC与BD交于点O△ABC为直角三角形△ACD△PAB△PBC均为等边三角形． 1求证PO⊥BD 2求二面角A﹣PD﹣C的余弦值．
WithitsGeorgianbrickbuildingsandgrassygreenhillsalmosteverywhereinBathfeelslikealivingpostcard.WithlandmarksfromRomanandmedievaltimesyoumayfeelyou'velandedbackintimebutthesplendidrowhousesandpeoplehustlingaboutonsmart﹣phonesbringsyououtofthatfantasy.Bathsomehowweavestogetherthreadsofsmall﹣townlifewithmetropolitanstyle.Ithasgalleriesmuseumsandtheaters.It'sacollegetownanchoredbytheUniversityofBath.AnditisaUNESCOWorldHeritagesite.EvenonameredaytripfromLondonjust90minutesawaybytrainBathbubblesoverwithcharm.BathAbbeyAnimpressivelandmarkinthecenteroftownBathAbbeyisthethirdplaceofworshiptooccupythissitein1200years.Thefirstchurchbuiltin757wasreplacedbyacathedralsoonaftertheNormanconquestofEnglandin1066.Thatonegavewayinthe15thcenturytotheAbbeythat'stheretoday.Walkinsideandeyetheceilingandstainedglasswindowsshowing56scenesfromChrist'slife.AfloorplatemarksQueenElizabethII's1973visit.Toursofthechurchtowerareavailable.RomanBathsTheRomanBathsdatebacktotheyear70withapoolofnaturalhotspringwatercalledtheGreatBathlocatedbelowstreetlevel.Youcanseethesteamswirlingonthestreetabove.Peopledressedinperiodclothing﹣suchasaRomansoldierorstonemason﹣standinthearchways.Thecomplexincludesseveralundergroundspacesanddisplays.Theself﹣guidedaudiotourthoroughlyexplainshowthecitizensofAquaeSulistheRomannamegiventoBathsocializedworkedandworshipped.Attheendofthetourvisitorscansamplesomeofthatrefreshingwater.JaneAustenCentreNovelistJaneAustenlivedwithfamilyinBathbetween1801and1806.AvidreadersofAusten'sworkknowthatBathwasaprominentsettingintwoofherbooksPersuasionandNorthangerAbbey.TheJaneAustenCentreathree﹣storybuildingonGayStreethasapermanentexhibitandtearoom.TheexhibitofferstwofloorsofclothesanecdotesaboutwhatdailylifewouldhavebeenlikeforAusteninBath.Youcanendyourwanderingwithafternoonteainthethird﹣floorRegencyTeaRoom.RoyalCrescentThishalf﹣moonformationofGeorgiantownhousesisoneofBath'smostfamousarchitecturalmasterpiecesanarc﹣shapedclusterofbuildingssetbehindagreenfield.ThefirsthomeNo.1RoyalCrescentwhereformerParliamentmemberHenrySanfordlivedinthelate1700sisalsoamuseum.Roomsarefurnishedin18thcenturystylewithaglimpseoftheupstairs﹣downstairslifestyleoftheerathinkDowntonAbbeybut150yearsearlier.1AccordingtothearticlethefollowingaspectsofBatharecoveredEXCEPT.A.historyB.architectureC.transportationD.accommodation2WhichofthefollowingstatementisINCORRECTaccordingtothepassage?A.BathAbbeyoccupiedthesiteinthe15thcenturyafterseveralhistoricalchanges.B.TheRomanBathsarefeaturedbyahotspringwaterwhereyoucantouraroundwiththelocalguide.C.TwoofJaneAustin'sbooksweresetinBathwhereshelivedfor5years.D.TheroomsinNo.1RoyalCrescentarefurnishedin18thcenturystyleresemblingthatofDowntonAbbey.
Thechangesfacingfastfoodcompanies Fastfoodwasoncethoughttoberecessionproof.WhenconsumersneedtocutspendingcheapmealslikeBigMacsandWhoppersbecomeevenmoreattractive.Asaresultfastfoodchainshavesurvivedtherecessionbetterthantheirmoreexpensivecompetitors.In2009salesatfullservicerestaurantsinAmericafellbymorethan6%buttotalsalesremainedaboutthesameatfastfoodchains.InsomemarketssuchasJapanFranceandBritaintotalspendingonfastfoodincreased. Butinthisongoingrecession萧条whichismoreseverenotallfastfoodcompanieshavebeenasfortunate.ManysuchasBurgerKinghaveseensalesfall.Intherecessionwhilesomepeopletradedowntofastfoodmanyotherseatathomemorefrequentlytosavemoney.SmallerfastfoodchainsinAmericasuchasJackintheBoxandCarl'sJr.havebeenhitparticularlyhardinthisdownturnbecausetheycutbackspendingonadvertising. Infaceofsuchchallengessomefastfoodcompanieshavesacrificedtheirownprofitsbytryingtogivecustomersbettervalue.Duringtherecessioncompaniessetpriceslowhopingtotemptmorecustomersthroughthedoor.Butinmanycasesthatstrategydoesn'twork.Somecompaniesarerethinkingtheirstrategies.KFChaslaunchedachickensandwichthatcostsaround﹩5toattractconsumersawayfrom﹩1specials. Companiesarealsotryingtogetcustomerstobuynewandmoreitemsincludingdrinks.McDonald'sstartedsellingbettercoffeeasachallengetoStarbucks.ItsMcCafelinenowaccountsforanestimated6%ofsalesinAmerica.Asfastfoodcompaniesshiftfromsupersizetomorebuystheyneedtokeepcustomertraffichighthroughouttheday.Manyseebreakfastasabigopportunityandnotjustforfattyfood.McDonald'shasstartedsellingporridgeinAmericabecausetheprofitscanbehigh. Butwhataboutthosegrowingwaistlines?Sofarfastfoodfirmshavecleverlyavoidedgovernmentregulation.Byprovidingoptionslikesaladsandlowcaloriesandwichestheyhaveatleastgiventheimpressionofdoingsomethingabouthelpingtofightobesity肥胖.Theseofferingsdon'tnecessarilyleadtoprofitlossastheycanbroadentheappealofstorestogroupsofdinersthatincludesomepeoplewhodon'twanttoeataburger. Butcallsfortoughergovernmentregulationneverweardown.ThisyearCongresspassedAmerica'shealthreformbillwhichrequiresrestaurantchainswith20ormorestorestoputthecaloriecontentofitemstheyservetothemenu.AndtherecentproposalbyacountyinCaliforniatobanMcDonald'sfromincludingtoysinitshighcalorieHappyMealsbecauselawmakersbelieveitattractschildrentounhealthyfoodsuggeststhatfastfoodcompanieswillhavetocontinuetryingsomethingnew. Thechangesfacingfastfoodcompanies
Sometimesweallgetthefeelingthatwearen'tmakingtheprogresswewanttoinlife.Perhapswedon'thavethecareerwewanttherelationshipwewantorthebodywewant.|Thisisasomewhatuniversalexperiencebutsomeofusfeelitmorestronglythanothers.Andwhenithasbeengoingonlongenoughwestarttolookforhelpfromoutsidesources.Thisiswherethelifecoachcomesinassomeonewhopromisestohelpussortourlivesoutandmakepositiveprogresstowardourgoals. Theeasiestwaytothinkofalifecoachisasapersonaltrainerforyourentirelife.Whileapersonaltrainermightwriteyouaprogramtohelpyougetinshapeandthenencourageyoutocarryoutthatprogramalifecoachwillgiveyouaprogramthatcanhelpyouinmultipleareasofyourlifeandthengiveyouthesamemotivationandencouragement.Ideallythisshouldmeandevelopinginyouthekindoftraitsandknowledgethatwilleventuallyallowyoutooutgrowyourneedforthem. Intheorythere'snothingwrongwiththeconceptoflifecoaching.Theissueinsteadcomesfromthefactthatthereisnoregulationinthismulti﹣milliondollarindustry.Ifyouareinterestedinbecomingalifecoachthenyoucanquiteeasilyapplyonlineandcompleteacourseforaround＄3000.Onecoursepromisesthatyoucanbecomeaqualifiedcoachinjustsixdays!Thisshouldberingingalarmbellsforanyonethinkingofhiringalifecoach.Thisissomeonewhoclaimstohavetheknowledgetohelpyouineveryaspectofyourlife.Howeverisitreallytrue?Ithinkit'sstillquestionable.Ofcoursethisdoesn'tmeanthatthereisnogoodlifecoach.Allitmeansisthattherearemaybadonesoutthereandthatit'sverydifficulttotellthemapartfromtheonesthatoffergenuinevalue. Thereforeit'simportanttorememberthatthebestlifecoachintheworldcanonlydosomuch.Behonestwithyourselfandaskyourselfwhetheryoureallyneedtoshifttheresponsibilityontosomeoneelse.Andyoushouldcertainlythinktwicebeforespendinglargeamountsofmoneyhiringalifecoachespeciallyifyou'recurrentlyunhappywithyourfinancialsituation!Additionallyyou'resupposedtoconsiderthefactthattherearemanyprofessionalswithfarmorequalificationsrelatingtovariousdifferentaspectsofyourlife.Youcanhireapersonaltrainertohelpyouwithfinancesandapersonalshoppertohelpyoupickoutyourclothes.Thiswillbringaboutfarmoregreatchangesthanthevastmajorityoflifecoachescan!
若xy满足约束条件则z＝2x﹣3y的最小值为．
已知双曲线的渐近线方程为y＝±x一个焦点F20则该双曲线的虚轴长为
YouhadbetterstayinChinaforfurthereducation.SometopAmericanuniversitiesareaccusedofAsianAmericanapplicantsusingraceasafactor. A.welcoming B.employing C.denying D.restoring
已知抛物线Cy2＝2pxp＞0直线y＝x﹣1与C相交所得的长为8．1求P的值2已知点O为坐标原点一条动直线l与抛物线C交于OM两点直线l与直线x＝﹣2交于H点过点H作y轴的垂线交抛物线C于N点求证直线MN过定点．
Ihavehadalifelongfascination﹣callitobsessionifyoulike﹣withcommunicationwithmakinglinkstootherplacesotherculturesotherworlds.Therootsofthisobsessionhaveoftenpuzzledme.Iamnot﹣neverhavebeen﹣agregariousperson.QuitetheoppositeIwasasolitarychildandmyclassmatesatschoolanduniversityalwaysthoughtofmeasaloner.Iwasnevercrazyaboutthenoisysolidarityofsocialgatherings.SowhywasIpossessedofadesiretomakecontactwithdistantplaces?ItcanpartlybeexplainedbythestartIhadinlife.Igrewuponwhatseemedatthetimeliketheedgeoftheworld﹣inaremotepartofruralIrelandinahouseholdwithfewbooksormagazinesandnotelevision.Foreigntravelwasunheardof.ApartfromthosewhoemigratedtoGreatBritainortheUnitedStatesvirtuallynobodyweknewhadeverbeenabroad.NobodyeverwentoverseasonholidayandnoforeignlanguagesweretaughtintheschoolsIattended﹣withtheexceptionofLatin.Welivedinaclosedsocietythatthoughtofitselfasself﹣sufficient.Therewashoweveronechinkoflightinthesuffocatinggloom﹣theradiowhichwecalled'thewireless.'Itwasbymodernstandardsahugeapparatuspoweredbyvalves﹣whichiswhyittooksometimetowarmup﹣anda'magiceye'tuningindicator﹣agreenishglasscirclethatwinkedatyouasthesignalwaxedorwaned.Thebestthingaboutourwirelessthoughwasthatithadashortwaveband.Thiswasthesourceofendlessfascinationtomebecauseitmeantthatevenwiththisprimitivedeviceonecouldlistentotheworld.AtfirstIcouldn'tunderstandhowitworked.Whywasreceptionsomuchbetteratnight?Whywasitsoinfuriatinglyvariable?Iaskedmyfatherwholookedevasiveandjustsaidithadsomethingtodowith'thewhachamacallitsphere'healwayscalledcomplicatedthingsthewhachamacallitbutthisgavemeenoughofasteertogotothelocallibraryandstartdigging.InduecourseIdiscoveredthathewasreferringtotheionosphere﹣alayerofchargedparticleshighupattheedgeoftheEarth'satmospherethatactsasakindofreflectorforradiowavesofcertainfrequencies.Thereasonshortwaveradiocouldtravelsuchhugedistanceswasthatitusedtheionospheretobouncesignalsroundtheworld﹣whichwaswhyradiohamsinLatinAmericaorAustraliacouldsometimesbeheardbyayoungboyonthewesternseaboardofIreland.Signalsfromsuchdistantshoresweremorelikelytogetthroughatnightbecausethentheionospherewashigherandtransmissionoverlongerdistanceswaspossible.Iwasspellboundbythisdiscoveryofhowtechnologycouldpiggybackonanaturalphenomenontopushforwardlow﹣powersignalsthroughimmensedistances.ButmostofallIwasentrancedbytheideaofshortwaveradioforthiswasatechnologywhichbelongednottogreatcorporationsorgovernmentsbuttopeople.Itwaspossiblemyfatherexplainedtoobtainalicensetooperateyourownshortwaveradiostation.Andallovertheglobepeopleheldsuchlicenseswhichenabledthemtositintheirbackroomsandbroadcasttothewholeworld.Theworldsuddenlyseemedwideopentome.1Thesecondparagraphprimarilyservesto.A.revealtheauthor'sattitudetowardforeignculturesB.presentinformationthatshedslightonacertainpreoccupationC.todisplaytheauthor'snostalgiaforhisadolescenceD.foreshadowthecrucialdifferencebetweentheauthorandhisfather2Theauthorconsidershisfather'sanswerinParagraph3tobe.A.incompletebuthelpfulB.humorousbutmeaningfulC.lightheartedyetconcernedD.sillyandconfusing3Whichofthefollowingiftruewouldmostweakentheclaimofoperatingashortwaveradiostation?A.ManygovernmentsaroundtheworlddonotregulateshortwaveusersB.ShortwaveequipmentisveryinexpensiveandisgettingcheaperallthetimeC.Mostindividualswhoapplyforshortwavelicensesareturneddown.D.CommunicationsexpertspredictthattheInternetwilleventuallyreplaceshortwaveradio.4Thepassageisprimarilyabouttheauthor's.A.decisiontopursueacareerinscienceB.acceptanceofhisfamily'sshelteredoutlookC.devotiontothestudyofemergingtechnologyD.discoveryofamedium'sliberatingpotential
某电商为某次活动设计了“和谐”“爱国”“敬业”三种红包活动规定每人可以依次点击4次每次都会获得三种红包的一种若集全三种即可获奖但三种红包出现的顺序不同对应的奖次也不同．员工甲按规定依次点击了4次直到第4次才获奖．则他获得奖次的不同情形种数为
已知复数z满足z1﹣i＝2﹣i其中i是虚数单位则复数z在复平面内对应的点位于
已知F1F2是椭圆+＝1的左右焦点点M的坐标为﹣1则∠F1MF2的角平分线所在直线的斜率为
在直角坐标系xOy中曲线C1的参数方程为α为参数以坐标原点O为极点x轴的正半轴为极轴建立极坐标系直线C2的极坐标方程为θ＝ρ∈R． 1求C1的极坐标方程 2若直线C2与曲线C1相交于MN两点求|MN|．
Raisingachildcanbebutitiswellworthit. A.overthemoon B.apieceofcake C.onitslastlegs D.aHerculeantask
ThepolarbearisfoundintheArcticCircleandsomebiglandmassesasfarsouthasNewfoundland.Whiletheyarerarenorthof88°thereisevidence1theyrangeallthewayacrosstheArcticandasfarsouthasJamesBayinCanada.Itisdifficulttofigureoutaglobalpopulationofpolarbearsasmuchoftherangehasbeen2poorstudied;howeverbiologistscalculatethatthereareabout20000﹣25000polarbearsworldwide. Modernmethods3trackingpolarbearpopulationshavebeenemployedonlysincethemid﹣1980sandareexpensive4performconsistentlyoveralargearea.InrecentyearssomeInuitpeopleinNunayut5reportincreasesinbearsightingsaroundhumansettlementsleadingtoa6believethatpopulationsareincreasing.Scientistshaverespondedby7notethathungrybearsmaybecongregating聚集aroundhumansettlementsleadingtotheillusion错觉thatpopulationsare8highthantheyactuallyare.Of9nineteenrecognizedpolarbearsubpopulationsthreearedecliningsix10bestableoneisincreasingandninelackenoughdata.
IsFreshAirReallyGoodforYou? Weallgrewuphearingpeopletellustogooutandgetsomefreshair.1AccordingtorecentstudiestheanswerisabigYESiftheairqualityinyourcampingareaisgood. 2Iftheairyou'rebreathingisclean﹣whichitwouldbeifyou'reawayfromthesmogofcities﹣thentheairisfilledwithlife﹣givingenergizingoxygen.Ifyouexerciseoutofdoorsyourbodywilllearntobreathemoredeeplyallowingevenmoreoxygentogettoyourmuscles肌肉andyourbrain. Recentlypeoplehavebegunstudyingtheconnectionbetweenthenaturalworldandhealing治愈.3Intheseplacespatientscangotobenearnatureduringtheirrecovery.Itturnsoutthatjustlookingatgreengrowingthingscanreducestresslowerbloodpressureandputpeopleintoabettermood情绪.Greeneryisgoodforus.HospitalpatientsWhoseetreebranchesouttheirwindowarelikelytorecoveratafasterratethanpatientswhoseebuildingsorskyinstead.4Itgivesusagreatfeelingofpeace. 5Whilethesun'srayscanageandharmourskintheyalsogiveisbeneficialVitaminD.TomakesureyougetenoughVitaminD﹣butstillprotectyourskin﹣putonsunscreenrightasyouheadoutside.Ittakessunscreenaboutfifteenminutestostartworkingandthat'splentyoftimeforyourskintoabsorbaday'sworthofVitaminD. A.Freshaircleansourlungs. B.Sowhatareyouwaitingfor? C.Beinginnaturerefreshesus. D.Anothersidebenefitofgettingfreshairissunlight. E.Butisfreshairreallyasgoodforyouasyourmotheralwayssaid? F.Justasimportantlywetendtoassociateairwithhealthcare. G.AllacrossthecountryrecoverycentershavebegunbuildingHealingGardens.
Allchildrenshouldgetaccesstoahigh﹣qualityeducationtheirracezipcodeorfamilyincome. A.dueto B.regardlessof C.apartfrom D.dependingon
如图平面四边形ABCD中∠BAD＝45°CB⊥ABCD⊥ADCD＝2CB＝1．则△ABD的面积为．
1Inwhichrestaurantcanyouhaveamealwithpeacefulcountrysurroundings?A.CHANGTOMTHAIRESTAURANTANDHOTELB.JACK'STRADITIONALANDAMERICANRESTAURANTC.MOGHULEXPRESSINDIANTAKEAWAYD.THEMARINARESTAURANT2Itcanbeconcludedthat.A.youcanenjoythefreshestlocalproduceinCHANGTOMTHAIRESTAURANTANDHOTELB.JACK'STRADITIONALANDAMERICANRESTAURANTsatisfiesalldifferenttastesC.youcanhaveyourorderdeliveredinMOGHULEXPRESSINDIANTAKEAWAYforanextrafeeD.THEMARINARESTAURANTprovidesthebestaccommodationofthefourrestaurants
IamimpressedwithChina'scommitmenttoitsclimategoalsevidencedbythefactwearesureofChinahasmetits2020targetsthreeyearsaheadofschedule. A.that B.which C.what D.where
NeedaJobThisSummer?Theprovincialgovernmentanditspartnersoffermanyprogramstohelpstudentsfindsummerjobs.Thedeadlinesandwhatyouneedtoapplydependontheprogram.Notastudent?Gotothegovernmentwebsitetolearnaboutprogramsandonlinetoolsavailabletohelppeopleunder30buildskillsfindajoborstartbusinessesallyearround.JobsforYouthIfyouareateenagerlivingincertainpartsoftheprovinceyoucouldbeeligible符合条件forthisprogramWhichprovideseightweeksofpaidemploymentalongwithtraining.Whoiseligible:Youth15﹣18yearsoldinselectcommunities社区.SummerCompanySummerCompanyprovidesstudentswithhands﹣onbusinesstrainingandawardsofupto$3000tostartandruntheirownsummerbusinesses.Whoiseligible:Studentsaged15﹣29returningtoschoolinthefall.StewardshipYouthRangerProgramYoucouldapplytobeaStewardshipYouthRangerandworkonlocalnaturalresourcemanagementprojectsforeightweeksthissummer.Whoiseligible:Studentsaged16or17attimeofhirebutnotturning18beforeDecember31thisyear.SummerEmploymentOpportunities机会ThroughtheSummerEmploymentOpportunitiesprogramstudentsarehiredeachyearinavarietyofsummerpositionsacrosstheProvincialPublicServiceitsrelatedagenciesandcommunitygroups.Whoiseligible:Studentsaged15orolder.Somepositionsrequirestudentstobe15to24orupto29forpersonswithadisability.1WhatisspecialaboutSummerCompany?A.Itrequiresnotrainingbeforeemployment.B.Itprovidesawardsforrunningnewbusinesses.C.Itallowsonetoworkinthenaturalenvironment.D.Itoffersmoresummerjobopportunities.2WhatistheagerangerequiredbyStewardshipYouthRangerProgram?A.15﹣18.B.15﹣24.C.15﹣29.D.16﹣17.3Whichprogramfavorsthedisabled?A.JobsforYouth.B.SummerCompany.C.StewardshipYouthRangerProgram.D.SummerEmploymentOpportunities.
设向量＝m0＝11且||2＝||2﹣|﹣|2则m等于
热门题库
更多
高一下学期化学
高一下学期物理
高三下学期数学
高三上学期数学
高一下学期英语
教案备课库
高一上学期生物
高一下学期生物
高二上学期数学
高二上学期物理
高二上学期英语
高二上学期生物
高二下学期数学
高二上学期化学
高二下学期物理
高三下学期物理
湘公网安备 43130202000226号