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已知x，y满足约束条件：，则z=2x+y的最大值是 ．
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已知xy满足约束条件则z=x+2y的最大值是
-3
-1
1
3
已知变量xy满足约束条件则z=2x+y的最大值为.
已知变量xy满足约束条件则z=2x+y的最大值为.
已知变量xy满足约束条件则z＝2x＋y的最大值为
4
2
1
－4
已知变量xy满足约束条件则z＝2x＋y的最大值为
4
2
1
－4
已知变量xy满足约束条件则z＝3x＋y的最大值为
12
11
3
－1
已知xy满足约束条件1求目标函数z=2x+y的最大值和最小值;2求目标函数z=2x-y的最大值和最小
若xy满足约束条件则z=x+y的最大值为_____________.
已知实数xy满足约束条件若目标函数z=x+y的最大值为4则实数a的值为.
已知xy满足约束条件若z=ax+y的最大值为4则a=
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已知xy满足约束条件则z=x+2y的最大值是
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已知变量xy满足约束条件则z＝2x·4y的最大值为___.
求函数u=xy+2yz在约束条件x2+y2+z2=10下的最大值和最小值．
已知实数xy满足约束条件则z=y-x的最大值为
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已知xy满足约束条件则z=x+2y的最大值是
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已知变量xy满足约束条件若z＝2x－y的最大值为3则实数m等于________.
已知变量xy满足约束条件则z=2x+y的最大值为.
已知变量xy满足约束条件若z=2x-y的最大值为2则实数m的值为.
设变量xy满足约束条件则目标函数z＝4x＋2y的最大值为
12
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8
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已知变量xy满足约束条件则z＝2x+y的最大值为
4
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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.
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After21yearsofmarriageBillHenrichsandMaryZieglerconcludedthattheywerenolongeragoodmatch.Thecouplepolitelydivorcedin1995andwenttheir1waysbuttheycontinuedtoseeeachotherwhenmeetingtheir2attheirschoolandsportingevents.InFebruary20183sheandHenrichslearnedtheywereamatchinadifferentway. Henrichs'skidneys肾were4andhewasinneedofa5.Afternearly40familymembersandfriendsweretestedaspossible6theresultsurprisedall﹣onlyoneperson7tobeaperfectmatch﹣Ziegler. SoonOct.16.morethanfourdecadesaftertheysaidIdosheandHenrichs62were8intoanoperatingroom.andoneofZiegler'shealthykidneyswas9andgiventoherex﹣husband.Thesurgerywentwellandthetransplantis10wellandcontinuingtoimproveasMr.Henrichs11fromthesurgery.Henrichswasbeyondgratefulforhisex﹣wife'ssympathyand12buthewasalsoworriedinthehoursbeforethe13. Justthreeweeksafterthetransplantshewasbacktoworkanddoingyoga﹣aquickturnaroundconsideringthatthe14kidneydonorneedsahealingperiodofsixtoeight15.Thisentireexperiencehasbroughtusall16.SheandHenrichshopethatbysharingtheirstoryother17willrealizethatdivorceisnotalwaysareasonto18ties. Divorceisdivorce.butthere'snoreasonto19Henrichssaid.Therearelotsofreasonswhyit's20togetalong.Hepausesandlaughs.Somedayyoujustmightneedakidney. 1A.separate B.peaceful C.opposite D.favorite 2A.parents B.colleagues C.kids D.neighbors 3A.moreover B.though C.therefore D.besides 4A.failing B.decreasing C.dying D.fading 5A.doctor B.supporter C.transplant D.receiver 6A.advocates B.donors C.volunteers D.fellows 7A.setout B.triedout C.rushedout D.turnedout 8A.wheeled B.called C.1ed D.dragged 9A.carried B.changed C.selected D.removed 10A.reacting B.functioning C.beating D.1iving 11A.refreshes B.returns C.remains D.recovers 12A.enthusiasm B.generosity C.optimism D.honesty 13A.marriage B.departure C.surgery D.decision 14A.routine B.kind C.uncommon D.average 15A.treatments B.times C.weeks D.operations 16A.closer B.farther C.deeper D.healthier 17A.friends B.schoolmates C.families D.children 18A.cutdown B.putoff C.putdown D.cutoff 19A.disturb B.quarrel C.regret D.cry 20A.important B.optional C.easy D.tough
An'adultingconference'ACthisweekallowedKentuckyhighschoolseniorsthechancetolearnhowtochangeatirehowtocookandotherbasiclifeskills﹣thingsthattheymaynothavelearnedathomeorinclasses.AseriesofphotospostedbyBullittCentralHighSchoolonsocialmediashowsstudentstaking'adultingconference'arelearningaboutpersonalfinancesresumesandotheressentialskillsattheeventwhichhasbeenwidelyreportedonthelocalandnationalnewsoutlets.'IsawaFacebookpostthatparentspassedaroundsayingtheyneededaclassinhighschoolontaxesandcooking'ACorganizerHardintoldLouisville'sWAVE3News.Thoseskillsaretaughtatschooltheoreticallyshesaidbuttheeventgavestudentsachancetofillingapsintheirknowledge.Studentscouldchoosetoattendthreeworkshopsoutof11totaloptionstheschoolsays.Theworkshopswereheldincooperationwithnumerouscommunitypartners.SomeyoungpeoplehavelefthomeandgraduatedschoolwithouthavingthosegapsfilledaccordingtoareportthisweekfromCBSNewYorkwhichdocumentedatrendofyoungpeopleseekingoutclassestolearnbasiclifeskills.Whileattendingacookingclass29﹣year﹣oldElenaToumarastoldthestationshe'sstrugglingwith'simplethings.''Iwassousedtowhenlivingathomemymomalwayscooking'shetoldthestation.An'AdultingSchool'inPortlandMaineaimstouseanewonlineformattoteachtheyouthsskillslikeconflictresolutionsewingandappreciationforallthestationsays.Students'financialliteracyhasbeenofparticularconcerntosomeexpertsasfinancialeducationinschoolshasstagnated停滞intheU.S.withonly17statesrequiringstudentstotakeclassesinpersonalfinance﹣anumberthathasn'triseninyears.'ThemajorityofU.S.statesarefailingourstudentsbydecliningtoofferthesefundamentalcourseswhicharecriticaltotheirfinancialstabilityandsecuritylaterinlife.Andthiswillbechanged.'NanJ.MorrisonpresidentandCEOoftheCouncilforEconomicEducationtoldCNBC.1Whatdoweknowaboutthe'adultingconference'?A.Itdrawsmuchattentionfromthemedia.B.Itisnottaughtathome.C.Itteachesseniorshowtobeareporter.D.Itisbroadcastlivetothepublic.2WhatcanwelearnfromwhatChristyHardinsaid?A.Onlytaxesandcookingclassesaledemanded.B.AChelpsputwhathasbeenlearntintopractice.C.ManyparentspassedbytheACclassroom.D.Theeventwasorganizedby.someparents.3WhydidElenaToumarasattendacookingclass?A.Todocumentatrend.B.Tostrugglewith'simplethings'.C.Tosatisfyhermother.D.Tolearnbasiclifeskills.4Whatcanweinferfromthelasttwoparagraphs?A.Expelswillbeconcernedaboutfinance.B.Fundamentalmajorswon'tbeprovidedinschools.C.Morefinancialcourseswillbeoffered.D.Morestateswilldeclinestudents'courses.
AcrossEuropewherevisitorscanoutnumberresidentsinthesummermonthsthecomplaintshavestarted.LastweekinBarcelonaanopen﹣topbuswasspray﹣paintedacrossitswindscreenwiththewords'TourismKillsNeighbourhoods'.Themessageisclear:suchcitiesareunderpressure.Intouristsandresidents'battleforsharedspaceslocalauthoritiesareuncomfortablyinthemiddle.Thetourismisoneofthelargestemployersintheworldwithonenewjobcreatedforevery30newvisitorstoadestination﹣butatwhatcosttolocals'qualityoflife?Morepeoplearetravellingthaneverbeforeandlowerbarrierstoentryandfallingcostsmeantheyaredoingsoforshorterperiods.Theriseof'citybreaks'﹣48﹣hourburstsofforeigncultures﹣hasincreasedtouristnumbers.'Toomanypeopledothesamethingattheexactsametime'saysXavierFontaprofessorattheUniversityofSurrey'Forlocalsthecitynolongerbelongstothem.'CompoundingtheproblemisAirbnbwhichhasmadetouristsmorecasualintheirapproachtointernationaltravelbutaddedtoresidents'headaches.ThosepermanentcitizenswhosharetheirapartmentblockswithAirbnbhostshavelosttheirpatience'Nolongerdowehavetosharethestreetswithtouristswehavetoshareourownbuildings!'Toeasethecongestionaroundthemainattractionsmanycitiesaretakingimmediateaction.Veniceisproposinganewconceptof'detourism':sustainabletraveltipsandalternativeroutesforexploringadifferentVenice.Agreatervarietyofguidanceforfuturevisitors﹣ideasforwhattodoinoff﹣peakseasonsforexample﹣canguidethemfromovercrowdedlandmarks.Repeatvisitorshaveabettersenseofthecultureanditismucheasiertointegratetheirbehaviourwithresidentsofthecities.'Butthelocalsshouldlearntotaketouristsasapartofurbanlife.Touristsdonothavetobeconsideredpassiveplayersbutratherasvisitorswithrightsandduties'saysFont'Everyonehasaparttoplayinpromotingthatchange.'1Whatproblemdothelocalauthoritiesoftenhaveinatouristcity?A.Thechallengecreatingmorebusinessforlocalpeople.B.Theconflicttakingplaceamongtouristsfromdifferentcountries.C.Thedilemmabetweentourismandlivingqualityofthelocals.D.Thecompetitionsamongthemostpopularattractions.2Whydothelocalresidentsreject'citybreak'accordingtoParagraphTwo?A.Toomanyvisitorshavedamagedthequalityoflife.B.Thelocalsfailtobenefitfromthecitybreakeconomically.C.Thelocalauthoritieslackadequateoperationguidance.D.Theyarereluctanttoshareanythingwithcomingtourists.3WhatisAirbnbmostprobably?A.Anewtravellingmapwithmorestreetinformation.B.AsolutionbyFonttoimprovethelocallivingquality.C.Asmalltownhavingthesamecomplaintsabouttourism.D.Awebsitetohelptravellersfindahomestay.4UndertheconceptofDetourismwhichofthefollowingshouldbeencouraged?A.Developingacitybreakduringon﹣seasons.B.Shiftingvisitorsfrombusyattractions.C.Attractingmorefirst﹣timevisitors.D.Takingtourismasapassivepartofurbanlife.
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ThepolarbearisfoundintheArcticCircleandsomebiglandmassesasfarsouthasNewfoundland.Whiletheyarerarenorthof88°thereisevidence1theyrangeallthewayacrosstheArcticandasfarsouthasJamesBayinCanada.Itisdifficulttofigureoutaglobalpopulationofpolarbearsasmuchoftherangehasbeen2poorstudied;howeverbiologistscalculatethatthereareabout20000﹣25000polarbearsworldwide. Modernmethods3trackingpolarbearpopulationshavebeenemployedonlysincethemid﹣1980sandareexpensive4performconsistentlyoveralargearea.InrecentyearssomeInuitpeopleinNunayut5reportincreasesinbearsightingsaroundhumansettlementsleadingtoa6believethatpopulationsareincreasing.Scientistshaverespondedby7notethathungrybearsmaybecongregating聚集aroundhumansettlementsleadingtotheillusion错觉thatpopulationsare8highthantheyactuallyare.Of9nineteenrecognizedpolarbearsubpopulationsthreearedecliningsix10bestableoneisincreasingandninelackenoughdata.
设xy满足约束条件则z＝x+y的最大值与最小值的比值为
已知i为虚数单位则复数=
IfAmericanwaterwayshadeverbeenvotedontheyearbooktheBuffaloRivercouldeasilyhavebeennamedUgliest.Itcouldbehardtofindhopethere.Ittookdecadesforpublicperceptionoftherivertoshift.Butactivistcitizenswhocollaboratedwithindustrygovernmentandenviron﹣ment～groups.nevergaveupontheirpollutedriver﹣theBuffaloRivergraduallywentfrombeingconsideredalostcausetoaplaceworthfighringfor.Andbynowthecleaned﹣upwaterisoneofBuffalo'Sbiggestattractions.Bythe1960stheriverwasseenasoneoftheworstsourcesofpollutionpouringintotheGreatLakes.TheBuffaloRiverhadcaughtfiremanytimes.Thesurfacehadanoilylayerandanyfishcaughttherewerenoteatable.Thewaterway'sfatestartedshiftinginthemid﹣1960s.StanleySpisiakwasalocalPolish﹣Americanjewelerbydaybutbyeveninghewasthekindofguywho'dchasedowndumpers垃圾车hespottedontheBuffaloRiver.By1966hefoundhimselfwinningtheNationalWildlifeFederation's'WaterConservationistoftheYear'award.Andbeforelonghegotanickname:'Mr.BuffaloRiver.'Buttherewasonlysomuchhecoulddo﹣theriverwasstilldeclaredbiologicallydeadin1969.JillSpisiakJedlickaishisgreat﹣grandniece.Shepicksupwhereheleftoffbydirectingtheriver'sprotectororganizationBuffaloNiagaraWaterkeeper.ProfessorSchneeklothandsevenfriendsfoundedtheorganizationasanall﹣volunteernonprofitin1989afterorganizingthefirstrivercleanupthatyear.Todaythegroupemploys27full﹣timeworkersandhashelpedoverseetheBuffaloRiver's＄100millionrestoration.SofartheBuffaloRiver'swaterqualityhasrestoredbutitisstillanongoingissueassewage污水canoverflowintotheriverafterstorms.Habitatrestorationcontinuesaswell;fishandplantingsarestillbeingsampledtomeasurehowwellit'sgone.1WhatdidtheBuffaloRiverusetobe?A.Awaterwayontheyearbook.B.Afiverheavilypolluted.C.AgreatattractionofBuffalo's.D.Aplaceworthfightingfor.2WhywasMr.Spisiaknamed'Mr.BuffaloRiver'?A.Becausehisfateshiftedinthe1960s.B.BecausehespotteddumpersontheRiver.C.Becausehesparednoeffortstoprotecttheriver.D.Becausetheriverwasdeclaredbiologicallydead.3Howlongdidittakeforthefivertorestore?A.Morethanhalfacentury.B.Justfourdecades.C.About30years.D.Only27years.4Whatcanbeasuitabletitleforthistext?A.TherestorationoftheBuffaloRiverB.StanleySpisiak:The'Mr.BuffaloRiver'C.ThefutureoftheBuffaloRiverD.Riverprotection:Alongwaytogo
Onourwaytothehouseitwasraining1hardthatwecouldn'thelpwonderinghowlongitwouldtake2getthere.ItwasinthemiddleofPearlCity. Wewerefirstgreetedwiththebarkingbyapack3dogsseventobeexact.Theywerewelltrainedbytheirmasters4hadgreatexperiencewithcaringfortheseanimals.Ourhostssharedmanyoftheirexperiencesand5recommendwonderfulplacestoeatshopandvisit.Forbreakfastwewereabletoeatpapaya木瓜andotherfruitsfromtheirtreesinthebackyard. Whentheywerefreefromworktheyinvitedustolocaleventsandletusknowofaninteresting6competetowatchtogetherwiththestorybehindit.Theyalsosharedwithusmany7traditionstoriesaboutHawaiithatwere8hugepopularwithtourists.Onthelastdayofourweek﹣longstaywe9invitetoattendaprivateconcertonabeautifulfarmontheNorthShoreunderthestars10listentomusiciansandmeetinginterestinglocals.
在平行四边形ABCD中A12B﹣20则点D的坐标为．
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在直角坐标系xOy中直线l的参数方程为t为参数以坐标原点为极点x轴的正半轴为极轴建立极坐标系圆C的极坐标方程为． 1若l与C相交于AB两点P﹣20求|PA|•|PB| 2圆M的圆心在极轴上且圆M经过极点若l被圆M截得的弦长为1求圆M的半径．
Morethan40percentofthespeciesthathelpwithpollination植物传粉areunderthreatduetothepollutedenvironment.Sosomeresearchershavebeensearchingforwaystoprotectthebeesandothercrucialpollinatorswhilesomeengineershavethoughtperhapsanarmyofroboticpollinatorscouldkeephumanswell﹣suppliedinthesefoods.Ateamofresearchershasrecentlydesignedasmalldronecapableofpollinatingflowers.Theytestedtheirdeviceonthelargepinkflowersoflilies.Anditworked.Excitingasthissuccesswasitisonlythefirststep.Theteamhasyettofigureouthowtoapplytheconceptonthemassivescale.Couldafleetofrobo﹣pollinatorsreplacethebees?'Althoughtheanswerisn'tastraightforwardnoitwouldbeachallengingleaptogofromthisonelittledronepollinatingonelargeflowertoanarmyofdronesspreadingacrossfieldsofcrops'saysScottSwintonanagriculturaleconomistatMichiganStateUniversity.'Thesuccessfulpollinationwasfascinating'ScottSwintonsays'butthedeviceitselfmightdamagetheflowers.Iwonderhowyoumakesureyou'renotdoingmoreharmthangoodtoflowerswhenyouhaveadrone.''Furthermore'hepointsout'alilyisaparticularlyeasyflowerforadronetopollinate.Tomakethismorebroadlyapplicableforsmallerandmorecomplexflowerstructuresthedroneswouldneedtobeparticularlyagile.'StillJoshuaCampbellanexpertattheUniversityofFloridasays'Pollinationsystemsareextremelycomplexandwillalwaysrequireinsects.Thereisnosubstituteforbees.''Asforthetechnologyitselfitisapromisingnewdevelopmentinexistingdronetechnology'headded.Yethestillseessomehurdlesaheadbeforedronescanbeappliedonalargescale.1Whatmakesthosescientistsinventpollinatingdrones?A.Therearenosatisfyingpollinators.B.Humansneedmorefoodsupplies.C.Pollinatingspeciesarebeingendangered.D.Dronetechnologyiswell﹣developednow.2WhatproblemdoesScottthinkscientistshavetosolvefortherobo﹣pollinators?A.Makingthemlooklikebees.B.Usingtheminquantity.C.Keepingthemflyingnon﹣stop.D.Instructingthemtotellplants.3Theunderlinedword'agile'inPara6canbereplacedby''.A.cheapB.catchyC.lovelyD.smart4What'sthebesttitleforthepassage?A.Willpollinatingdronestakeoverforhoneybees?B.Whatisleadingpollinatinghoneybeestodecline?C.Whydoespollinatingneedamoney﹣savingoption?D.Howdidresearchersinventpollinatingdrones?
Inanonlineclassdevelopinghealthypatternsofcommunicationwithprofessorsisveryimportant.1WhileIhaveonlylistedtwoofeachthereareobviouslymanyothersituationsthatcanarise.Studentsshouldbeabletoextendthelogic逻辑ofeachtotheirparticularcircumstance. Do's •2Questionsaboutsubjectcontentaregenerallywelcomed.Beforeaskingquestionsaboutthecoursedesignreadthesyllabus教学大纲andlearningmanagementsysteminformationtobesuretheanswerisn'thidinginplainsight. •Participateindiscussionforums论坛blogsandotheropen﹣endedforumsfordialogue.3Besuretostayontopicandnotofferirrelevantinformation.Makeapointandmakeitsafeforotherstodothesame. Don'ts •Don'tsharepersonalinformationorstories.Professorsarenottrainednursesfinancialaidexpertsoryourbestfriends.Ifyouareinneedofadeadlineextensionsimplyexplainthesituationtotheprofessor.4 •Don'topenlyexpressannoyanceataprofessororclass.5Whenastudentattacksaprofessoronthesocialmediathelanguageusedactuallysaysmoreaboutthestudent.Ifthereistrulyaconcernaboutaprofessor'sprofessionalismorabilitybesuretouseonlinecourseevaluationstocalmlyofferyourcomments. A.That'swhattheyarefor. B.Turntoanonlineinstructorforhelp. C.Ifmoreinformationisneededtheywillask. D.Rememberthatonlineprofessorsgetalotofemails. E.Belowaresomecommondo'sanddon'tsforonlinelearners. F.Everyonehastakenanot﹣so﹣greatclassatonetimeoranother. G.Askquestionsbutmakesuretheyaregoodthoughtfulquestions.
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.
将函数fx＝cos4x﹣的图象上各点的横坐标伸长到原来的2倍纵坐标不变得到函数y＝gx的图象则gx的最小正周期是
若函数fx＝有最大值则a的取值范围为
OPENINGSANDPREVIEWSAnimalsOutofPaperYolo!ProductionsandtheGreatGriffonpresenttheplaybyRajivJosephinwhichanorigami折纸术artistinvitesateenagetalentandhisteacherintoherstudio.MerriMilwedirects.Inpreviews.OpensFeb.12.WestParkPresbyterianChurch165W.86thSt.212﹣868﹣4444.TheAudienceHelenMirrenstarsintheplaybyPeterMorganaboutQueenElizabethIIoftheUKandherprivatemeetingswithtwelvePrimeMinistersinthecourseofsixtyyears.StephenDaldrydirects.AlsostarringDylanBakerandJudithIvey.PreviewsbeginFeb.14.Schoenfeld236W.45thSt.212﹣239﹣6200.HamiltonLin﹣ManuelMirandawrotethismusicalaboutAlexanderHamiltoninwhichthebirthofAmericaispresentedasanimmigrantstory.ThomasKaildirects.Inpreviews.OpensFeb.17.Public425LafayetteSt.212﹣967﹣7555.OntheTwentiethCenturyKristinChenowethandPeterGallagherstarinthemusicalcomedybyBettyComdenandAdolphGreenaboutaBroadwayproducerwhotriestowinamoviestar'sloveduringacross﹣countrytrainjourney.ScottEllisdirectsforRoundaboutTheatreCompany.PreviewsbeginFeb.12.AmericanAirlinesTheatre227W.42ndSt.212﹣719﹣1300.1WhatistheplaybyRajivJosephprobablyabout?A.Atypeofart.B.Ateenager'sstudio.C.Agreatteacher.D.Agroupofanimals.2WhoisthedirectorofTheAudience?A.HelenMirren.B.PeterMorgan.C.DylanBaker.D.StephenDaldry.3WhichplaywillyougotoifyouareinterestedinAmericanhistory?A.AnimalsOutofPaper.B.TheAudience.C.Hamilton.D.OntheTwentiethCentury.
某厂销售部以箱为单位销售某种零件每箱的定价为200元低于100箱按原价销售不低于100箱通过双方议价买方能以优惠8%成交的概率为0.6以优惠6%成交的概率为0.4． 1甲乙两单位都要在该厂购买150箱这种零件两单位各自达成的成交价相互独立求甲单位优惠比例不低于乙单位优惠比例的概率 2某单位需要这种零件650箱求购买总价X的数学期望．
Beforethe1830smostnewspapersweresoldthroughannualsubscriptionsinAmericausually﹩8to﹩10ayear.Today﹩8or﹩10seemsasmallamountofmoneybutatthattimetheseamountswereforbiddingtomostcitizens.Accordinglynewspaperswerereadalmostonlybyrichpeopleinpoliticsorthetrades.Inadditionmostnewspapershadlittleinthemthatwouldappealtoamassaudience.Theyweredullandvisuallyforbidding.Buttherevolutionthatwastakingplaceinthe1830swouldchangeallthat.Thetrendthenwastowardthe'pennypaper'﹣atermreferringtopapersmadewidelyavailabletothepublic.Itmeantanyinexpensivenewspaper;perhapsmoreimportantlyitmeantnewspapersthatcouldbeboughtinsinglecopiesonthestreet.Thisdevelopmentdidnottakeplaceovernight.Ithadbeenpossiblebutnoteasytobuysinglecopiesofnewspapersbefore1830butthisusuallymeantthereaderhadtogodowntotheprinter'sofficetopurchaseacopy.Streetsaleswerealmostunknown.Howeverwithinafewyearsstreetsalesofnewspaperswouldbecommonplaceineasterncities.Atfirstthepriceofsinglecopieswasseldomapenny﹣usuallytwoorthreecentswascharged﹣andsomeoftheolderwell﹣knownpaperschargedfiveorsixcents.Butthephrase'pennypaper'caughtthepublic'sfancyandsoontherewouldbepapersthatdidindeedsellforonlyapenny.Thisnewtrendofnewspapersfor'themanonthestreet'didnotbeginwell.Someoftheearlyventures企业wereimmediatefailures.Publishersalreadyinbusinesspeoplewhowereownersofsuccessfulpapershadlittledesiretochangethetradition.Ittookafewyouthfulanddaringbusinessmentogettheballrolling.1WhichofthefollowingbestdescribesnewspapersinAmericabeforethe1830s?A.Academic.B.Unattractive.C.Inexpensive.D.Confidential.2Whatdidstreetsalesmeantonewspapers?A.Theywouldbepricedhigher.B.Theywoulddisappearfromcities.C.Theycouldhavemorereaders.D.Theycouldregainpublictrust.3Whowerethenewspapersofthenewtrendtargetedat?A.Localpoliticians.B.Commonpeople.C.Youngpublishers.D.Richbusinessmen.4Whatcanwesayaboutthebirthofthepennypaper?A.Itwasadifficultprocess.B.Itwasatemporarysuccess.C.Itwasarobberyofthepoor.D.Itwasadisasterforprinters.
在正方体ABCD﹣A1B1C1D1中则异面直线AC1与BE所成角的余弦值为
假定你是李华你校将举办音乐节.请写封邮件邀请你的英国朋友Allen参加内容包括: 1.时间; 2.活动安排; 3.欢迎他表演节目. 注意: 1.词数100左右; 2.可以适当增加细节以使行文连贯.
Itwasthebiggestnightofmylife一openingnight.Hoursof1anddailyrehearsalshadgoneintothisproduction.Ihadrecitedmylineathousandtimes2thatmyonesentencewouldbethehighlightoftheshow. Asa7﹣year﹣oldboyIwas3toperforminanactualmusical.ThenightbeforeIhad4mycostumeonthebed:awhiteshirtbluejeans?andmyhandmadenecklace. My5wasgoingtobespeciallydone.Mylipswouldbeinbeautifulred.Iwas6preparedtobetheshiningstarinmyclass'sperformanceofthemusicalOneBigHappyFamily. Alittletimebeforetheplaythebackstagewascomplete7.MyfriendandIdressedinourcostumesweregiggling.Childrenwererunningaroundmadly.Somewere8aboutforgettinglines;othersweresingingvarioussongsoutoftune.Itwasabiggroupof9secondgradersabouttomaketheirfirstperformance. Soonthebigmomentcameandweallfiledontothestage10theaudienceofparentsandrelatives.The11beganandmysecondgradeclassstartedsingingwithsweetseven﹣year﹣oldvoices.Isangmylittleheart12hopingtomaketheshowasperfectasI'd13. Myturntospeak!Thekidstandingnexttomehandedoverthemicrophonetome.AsIstartedtospeakInoticedsomethinghadgonehorribly14一themicrophonewasnotturnedon.Thebloodrushedtomyfaceimmediately.15Iturneditoverandswitchedthedeviceon.AftersayingmylineasquicklyaspossibleIhandedthemicrophoneoffandIjustfeltthatIhad16. Everybodyisexcellent!''theteacher17usinthebackstage.I'msorryMissAlex.Isaidtoher.18tobesorryaboutHoney.ShesmiledtomeNoteverysurpriseinourlifeisalwayssopleasant.Youdidagoodjob! Ifeltso19inaminuteandIcanhardlywaittotellmydadandmumthestoryoftheunpleasant20. 1A.experiments B.preparations C.descriptions D.introductions 2A.informed B.confirmed C.amazed D.convinced 3A.eager B.grateful C.scared D.accustomed 4A.laidout B.hungup C.turnedout D.madeup 5A.head B.heart C.hair D.feet 6A.deliberately B.thoroughly C.possibly D.nervously 7A.party B.silence C.tension D.chaos 8A.panicking B.arguing C.greeting D.thinking 9A.relaxed B.timid C.excited D.confused 10A.leaving B.facing C.playing D.greeting 11A.show B.line C.rehearsal D.practice 12A.in B.down C.of D.out 13A.found B.imagined C.declared D.calculated 14A.blank B.wrong C.numb D.mad 15A.Impatient B.Enthusiastic C.Embarrassed D.Determined 16A.pickedup B.mixedup C.cheeredup D.messedup 17A.admired B.criticized C.praised D.taught 18A.Everything B.Something C.Nothing D.Anything 19A.proud B.relieved C.puzzled D.interested 20A.surprise B.lesson C.program D.performance
过点M﹣10引曲线Cy＝2x3+ax+a的两条切线这两条切线与y轴分别交于AB两点若|MA|＝|MB|则a＝．
如图在多面体ABCDEF中四边形ADEF为正方形AD∥BCAD⊥ABAD＝2BC＝1． 1证明平面ADEF⊥平面ABF． 2若AF⊥平面ABCD二面角A﹣BC﹣E为30°三棱锥A﹣BDF的外接球的球心为O求二面角A﹣CD﹣O的余弦值．
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.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. Laughingisoneoflife'smostsimplepleasure.Itisfree.Youcandoitanywhere.Liketheflulaughtercanspreadeasyamongpeople.Oftenwhenwehearsomeonelaughingincrowdedroomorapackedtrainwestartlaughingtoo﹣evenifwehavenoideahow. Infactmentalhealthcanaffectonphysicalhealth.ThereforeLaughteristhebestmedicinedoesnotmeanthatIshouldnottakemedicinewhenyou'resick.Itsimplymeansthathaveapositiveoutlookmighthelpeaseyourtroublesbutmakeyoucheerful.Besidesmakingotherslaughwithyouisalsoanactwhatisjoyfulandkind.
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