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如图，玻璃柱的横截面为半径R＝20.0cm的半圆，O点为圆心．光屏CD紧靠在玻璃柱的右侧且与截面底边MN垂直．一光束沿半径方向射向O点，光束和MN的夹角为θ，在光屏CD上出现两个光斑．已知玻璃的折射...
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如图玻璃柱的横截面为半径R＝20.0cm的半圆O点为圆心．光屏CD紧靠在玻璃柱的右侧且与截面底边M
两束平行的细激光束垂直于半圆柱玻璃的平面射到半圆柱玻璃上如图所示已知其中一条光线沿直线穿过玻璃它的入
一个半圆柱形玻璃砖其横截面是半径为R的半圆AB为半圆的直径O为圆心如图所示玻璃的折射率为n=2 i一
一半径为R.的半圆形玻璃砖横截面如图所示已知玻璃的全反射临界角rr
一半径为R.的半圆形玻璃砖横截面如图所示已知玻璃的全反射临界角rr
半径为R.的玻璃半圆柱体横截面如图11所示圆心为O..两条平行单色红光沿截面射向圆柱面方向与底面垂直
一个半圆柱形玻璃砖其横截面是半径为R.的半圆AB为半圈的直径O.为圆心如图所示玻璃的折射率为i一束平
半径为R.的玻璃半圆柱体横截面如图所示圆心为O.两条平行单色红光沿截面射向圆柱面方向与底面垂直光线1
一个半圆柱形玻璃砖其横截面是半径为R.的半圆AB为半圆的直径O.为圆心如图所示玻璃的折射率为i一束平
如图玻璃柱的横截面为半径R＝20.0cm的半圆O点为圆心．光屏CD紧靠在玻璃柱的右侧且与截面底边M
玻璃半圆柱体横截面如图所示．O为圆心A为半圆形的最高点圆的半径为R．单色光束按如图方向沿截面入射到
两束平行的细激光束垂直于半圆柱玻璃的平面射到半圆柱玻璃上如图所示.已知其中一条光线沿直线穿过玻璃它的
如图玻璃柱的横截面为半径R=20.0cm的半圆O点为圆心．光屏CD紧靠在玻璃柱的右侧且与截面底边MN
两束平行的细激光束垂直于半圆柱玻璃的平面射到半圆柱玻璃上如图所示已知其中一条光线沿直线穿过玻璃它的入
一个半圆柱形玻璃砖其横截面是半径为R.的半圆AB为半圆的直径O.为圆心如图所示玻璃的折射率n=.i一
两束平行的细激光束垂直于半圆柱玻璃的平面射到半圆柱玻璃上如图所示.已知其中一条光线沿直线穿过玻璃它的
半径为R.的玻璃半圆柱体横截面积如图所示圆心为O.一束平行单色红光沿截面射向圆柱面方向与底面垂直左边
半径为R的玻璃半圆柱体横截面如图所示圆心为O两条平行单色红光沿截面射向圆柱面方向与底面垂直光线1的入
一半径为R.的半圆形玻璃砖横截面如图所示O.为圆心一束平行光线照射到玻璃砖MO′面上中心光线a沿半径
半径为R.的半圆柱形玻璃横截面如图所示O.为圆心已知玻璃的折射率为当光由玻璃射向空气时发生全反射的临
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已知抛物线Cy2＝2pxp＞0过点P30的任意一条直线与抛物线交于AB两点抛物线外一点Qt0若∠OQA＝∠OQB则t的值为
Helpfulwaystodealwithaknow﹣it﹣allfriend Sometimeshavingafriendwhothinkssheknowseverythingandalwaysoffersherunsolicited主动提供的advicecanreallymakeoneupset.Butwithsomewaystodealwithknow﹣it﹣allyoucaneasilycopewiththatfriend.Alsoaknow﹣it﹣allfriendoftenactsasifshewerethebest.1 Trytounderstand.Theremaybeareasonwhyyourknow﹣it﹣allfrienddoesso.Maybeshehaslowself﹣esteem自尊orshesnothappyinherlife.2Thistipisveryimportantespeciallyiftheknow﹣it﹣allisyourbestfriend GiveheralittleattentionGivingalittleattentionisoneofthebestwaystodealwithaknow﹣it﹣allfriend.Showsomeenthusiasmaboutwhattheknow﹣it﹣allsaystogiveherenoughattention3Orthiscanleadtohergivingmoreunsolicitedadvice4Oftentheknow﹣it﹣allfriendcansaysomenot﹣so﹣nicethingsandthesethingsareusuallyaboutyou.Insteadofthinkingthatsomethingisnotokaywithyounevertakehercommentsandadvicepersonally.Ifyoudoso.youmayreallybegintobecomeunnecessarilyanxious. Haveatalkwithher.Ifyouresickandtiredofallthoseunsolicitedadvicecomerightoutwithit.Speakpolitelyanddon'tinsult辱骂her.Trytofindagoodtimetotalktoher.5.Tellyourknow﹣it﹣allfriendhowitmakesyoufeelandmaybeshewillrespondwell. A.Feelfreetoignoreherallthetime. B.Don'ttakehercommentspersonally. C.Howevermakesureyoudon'toverdoit D.Trynottogotothoseplaceswhereyouthinkshellbe D.Trynottogotothoseplaceswhereyouthinkshellbe E.Ifyouhavesuchafriendhereareafewtipsoncopingwithher F.Trytounderstandherandunderstandwhysheactsthewaythatshedoes. G.Youneedtoknowwhatyouregoingtosayandbesuretouseonlykindwords
UpcomingMusicfestivalsandconcertsinBostonin2019 NewBedfordFolkFestival2019 The24thAnnualNewBedfordFolkFestivalwillfeaturethebestincontemporarytraditionalandCelticfolkmusic.CalledoneofthemostexcitingandsmartlyprogrammedfestivalsintheNortheastandNewEngland'smostenjoyablefolkfestivalNewBedfordFolkFestivalisanaffordabledestinationforfamiliesseekingafun﹣filledweekend. ●LocationWaterfrontNewBedfordMA ●Phone617999﹣5231 ●DatesSaturdayJuly62019一SundayJuly72019 ●HoursSaturdayandSundayJuly7and8from1100AM.to700PM. ●In/OutdoorOutdoor ●Cost﹩289perfamilylimit4membersperfamily﹩59perticketformorethan4 BostonCallingMusicFestival2019 BostonCallingMusicFestivalisathree﹣daytwo﹣stagefestivalfeaturingsomeofthebiggestandbestactsinlivemusic!!ThemusicalcelebrationtakesplaceattheHarvardSportsComplexwitheasyaccesstostagesawidevarietyoffoodservicesandmore.Allagesarewelcomeandchildrenunder10arefree ●LocationHarvardSportsComplexAllstonMA ●Phone617536﹣4100 ●DatesFridayJuly192019一SundayJuly212019 ●HoursFriday6PM﹣1.1PMSaturday/Sunday12AM﹣I1PM ●In/OutdoorOutdoor ●Cost﹩98perpersonchildrenunder10free LevitateMusic&ArtsFestival2019 JoinusforadayofmusicartfoodandtheoutdoorsattheMarshfieldFairgrounds!Therewillbelotsofmusicarts&craftsanddeliciousfoodtruckstoenjoy! ●Location140MainStreetMarshfieldMA02050 ●Phone617635﹣4505 ●DatesFridayJuly122019•SundayJuly142019 ●Hours1200AM﹣8OOPM ●In/OutdoorOutdoor ●Cost3DayTickets﹣﹩109advanceGA﹩269advanceVIP.Kidsunder12Free JazzintheParkSummerConcertSeries2019 NempacPresentsJazzintheParkSummerConcertSeries2019everyTuesdayfromJuly23thtoJuly30that600prn﹣730pm.Comeandenjoywithus! ●LocationParcel10BostonMA02113map ●Phone617227﹣2270 ●DatesJuly23thtoJuly30th ●Hours600PM一800PM ●In/OutdoorOutdoor ●Cost150perpersonChildrenunder18free. 1Whichfestivalwouldyouliketogoifyouhavespecialinterestinfolkmusic? A.NewBedfordFolkFestival2019. B.BostonCalling.MusicFestival20119. C.LevitateMusic&ArtsFestival2019. D.JazzintheParkSummerConcertSeries2019. 2WhichnumbershouldyoudialifyouwanttolearnmoreinformationabouttheJazzconcert? A.617635﹣4505 B.617227﹣2270 C.617999﹣5231 D.617536﹣4100 3Whatdothefoureventshaveincommon? A.Theyareforfamilies. B.Theylastforthreedays. C.Theytakeplaceoutdoors. D.Theydon'tchargechildren.
Leila'sHairMuseum Beforetheinventionofphotographypeoplekeptmemoriesoflovedonesbycreatingmementos纪念物usinghumanhair．In1986LeilaCohoonopenedamuseuminIndependenceMissouritoshowhercollectionofmorethan2000piecesofhair﹣basedartcollectedover30years．Billedastheonlyhairmuseumintheworlditincludesmorethan400braidedhairwreaths花环and2000piecesofjewellerydatingbacktothemid﹣1600s．Mymuseumisfilledwithotherpeople'sfamiliesLeilasays．Ittellsastory． InternationalUFOMuseumandResearchCenter OnJuly71947afarmerdiscoveredmysteriousmetallicdebris金属碎片inhisfarmoutsideRoswellNewMexico．RoswellArmyAirFieldRAAForiginallysaiditrecoveredaflyingdisc．ThenextdayRAAFchangeditswordsTheobjectwasaweatherballoon．StoriesofaUFOandagovernmentcover﹣upspread．Eachyear180000peoplecheckoutthedirtfromtheUFOcrashsitephotosandreportsabouttheRoswellincident． MuseumofBadArt Notallartiscreatedequal．Afterfindinganoilpaintingintherubbishin1993﹣thenowclassicLucyintheFieldwithFlowers﹣ScottWilsonstartedcollectingbadart．BeforelongheshowedhisfindsattheSomervillemovietheater．TheMuseumofBadArtMOBAgivesthepublicafirsthandlookatsomeoftheworld'sworstdisaster﹣pieces．PopularpaintingsincludeManaLisaHollywoodLipsandDrillingforEggs．MOBAisalwaysonthelookoutforthebestoftheworstsaidco﹣founderMarieJackson．Butwhatanartistconsiderstobebaddoesn'talwaysmeetourlowstandards． MutterMuseum WelcometotheMutterMuseuminPhiladelphiaPennsylvania﹣hometomorethan5000brainsbonesanddeadbodies!In1858Dr．ThomasDentMuttergavehiscollectionofpreservedbodypartsandbonestotheCollegeOfPhysicianstoimprovemedicaleducationwhichledtothemuseum'screationin1863．TodayMutteristhemostfamousmedicalmuseuminAmericahousingawallofbonesandpiecesofAlbertEinstein'sbrain． 1WhatisspecialaboutLeila'sHairMuseumA A．Itisfulloffamilystories． B．Ithousestheworld'sgreatestphotos． C．Itholdscollectionsfromaroundtheglobe． D．ItwasopenedtorememberLeila'slovedones． 2WhatcanyoufindintheMutterMuseumB A．PhotosabouttheRoswellincident． B．SomeofAlbertEinstein'sbrain． C．2000piecesofjewellery． D．ManaLisa． 3WhatdothefourmuseumshaveincommonD A．Theyarenewly﹣foundedmuseums． B．Theyareart﹣centered． C．Theyareunpopularamongvisitors． D．Theyarequiteunusual．
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Digitalgrounding限制iswhenparentsorcaregiverslimitorcompletelytakeawayaccesstotechnologyfromchildren.AccordingtoastudyconductedbyPewResearch65%ofparentshavedigitallygroundedtheirteenbytakingawaytheirteen'scellphoneorInternetaccessaspunishment. Becausechildrenaresoconnectedwiththeirtechnologiesdigitalgroundingmayseemlikealogicalstepforparents.Takeawayachild'smostcherisheditemandtheywillquicklylearnfromtheirbehavior.Buttheideaofdigitalgroundingisn'tasclear﹣cutasthat.Insteaditmaybealose﹣losesituationforparentsandkidsalike. Formostparentsthegoalofgroundingisn'ttomaketheirchildrenunhappyorsad.Itistoteachalessoninthehopethattheywon'tengageinwhateverbehaviorgotthemintroubleinthefirstplace.Unfortunatelythoughdigitalgroundingisoftenjustpunishmentnotdiscipline.Ifachildstaysoutpastcurfew约定的最晚回家时间apunishmentwouldbehittingoryellingatthem.Disciplinewouldbenotlettingthemgooutthenextweekendbecausetheyfailedtofollowrules. We'veallbeenthere﹣we'vecaughtourchilddoingsomethingwrongandintheheatofthemomentlaidoutastrictpunishment.Wemayhavebeenfeelinghot﹣headedembarrassedorupset.Oftenthoughthesepunishmentsdon'talign结盟withthebadbehavior. Whiledigitalgroundingmaysolvetheproblemtemporarilyitwon'tprovidechildrenwiththeguidancetheyneedtoactappropriatelyinthefuture.Insteadofgroundingshowyourchildwhattheydidwrongandgivethemthechancetoactdifferently. Thiswaytheywilllearnfromtheirmistakesinapracticalmannerandfigureoutwaystobesafeandsmartwithtechnology. There'snodenyingittechnologyishereforthelong﹣haul.Thisiswhysomeparentingexpertsdon'trecommenddigitallygroundingyourchildren.Itdoesn'tfocusontheendgoalofsafebehavior.Theyrecommendteachingthemgoodhabitsassoonaspossibleratherthantakingawaytheirtechnology.Bydigitallygroundingthemyouareputtingabandageoverthewoundratherthantreatingit. Nowwhenwesaythatdigitalgroundingisalose﹣losesituationwe'renotsayingthatdiscipliningyourchildreningeneralisalose﹣losesituation.Disciplineisagreatwaytoteachchildrenlessonswhenusedappropriately. 1Whichofthefollowingisaproperformofdisciplineaccordingtotheauthor? A.Hittingoryellingatchildren. B.Layingoutastrictpunishmentintheheatofthemoment. C.Takingawayaccesstocellphonesfromchildrencompletely. D.Forbiddingkidstogooutthenextweekendiftheystayoutpastcurfew. 2Whatdoestheauthorthinkofdigitalgrounding? A.Itbenefitschildrenagreatdeal. B.Itisnobetterthandisciplining. C.Parentscanuseittocorrectkids'behavior. D.Neitherparentsnorchildrengainbenefitsfromit. 3Whatdoestheauthorsuggestparentsdoinsteadofgrounding? A.Givekidsmorefreetime. B.Helpkidsformgoodhabits. C.Actappropriatelyinpublic. D.Putabandageoverthewound. 4What'sthepurposeofthetext? A.Toinformusofwaysofpunishingkids. B.Toexplainwhatdigitalgroundingmeans. C.Toshowhowtoparentchildrenindigitaltimes. D.Toprovedigitalgroundingisnotagoodparentingway.
IfplastichadbeeninventedwhenthePilgrimssailedfromPlymouthEnglandtoNorthAmerica﹣andtheirMayflowerhadbeenstockedwithbottledwaterandplastic﹣wrappedsnackstheirplasticwastewouldlikelystillbearoundfourcenturieslater.Atlanticwavesandsunlightwouldhavewornallthatplasticintotinybits.Andthosebitsmightstillbefloatingaroundtheworld'soceanstodaywaitingtobeeatenbysomefishoroysterandfinallyperhapsbyoneofus. Becauseplasticwasn'tinventeduntilthelate19thcenturyanditsproductiononlyreallytookoffaround1950wehaveamere9.2billiontonsofthestufftodealwith.Ofthatmorethan6.9billiontonshavebecomewaste.Andofthatwasteasurprising6.3billiontonsnevermadeittoarecyclingbin﹣thefigurethatshockedthescientistswhopublishedthenumbersin2017. Nooneknowshowmuchunrecycledplasticwasteendsupintheoceantheearth'slastsink.In2015JennaJambeckaUniversityofGeorgiaengineeringprofessorcaughteveryone'sattentionwitharoughestimatebetween5.3millionand14milliontonsofplasticwasteeachyearjustcomefromcoastalregions. Meanwhileoceanplasticisestimatedtokillmillionsofmarine海洋的animalseveryyear.Nearly700speciesincludingendangeredonesareknowntohavebeenaffectedbyit.Someareharmedvisiblystuckbyabandonedthingsmadeofplastic.Manymoreareprobablyharmedinvisibly.Marinespeciesofallsizesfromzooplanktontowhalesnoweatmicroplasticsthebitssmallerthanone﹣fifthofaninchacross. Thisisn'taproblemwherewedon'tknowwhatthesolutionissaysTedSiegleraVermontresourceeconomistwhohasspentmorethan25yearsworkingwithdevelopingnationsongarbage.Weknowhowtopickupgarbage.Anyonecandoit.Weknowhowtodealwithit.Weknowhowtorecycle.It'samatterofbuildingthenecessaryinstitutionsandsystemshesaysideallybeforetheoceanturnsintoathinsoupofplastic. 1WhydoestheauthormentionthePilgrimsinparagraph1? A.Toproveplasticwasdifficulttoinvent. B.Tointroducewhatmarineanimalslikeeating. C.TotellthePilgrimscontributedalottothemarineprotection. D.Toshowplasticwastehasalastingeffectontheocean. 2What'sthemaintroublemarineanimalsfaceaccordingtothetext? A.Lackingprotection. B.Beingstuckbyplastics. C.Beingcaughtbyhumans. D.Treatingplasticsasfood. 3WhatdoesTedSieglerwanttotellusinthelastparagraph? A.Somepeopledon'tknowthesolutionofplasticswaste. B.Plasticswillturntheoceanintoasoupofplastic. C.It'stimetotakemeasurestodealwithplasticwaste. D.Peopleshouldavoidusingplasticstoprotecttheocean. 4Fromwhichisthetextprobablytaken? A.Abiologytextbook. B.Atravelbrochure. C.Anenvironmentalreport. D.Alifestylemagazine.
StanLeewasborninManhattanNYonDecember281922.UpongraduatingfromDeWittClintonHighSchoolthe16﹣year﹣oldwashiredatwhatwasthencalledTimelyPublications.Thecompanywasbestknown1inexpensivefiction.In1941he2givehisfirstchancetowriteastory. 3promotetotheeditorofthecomicbookdivisionattheageof19.Leespentthenextdecadewritinga4variousofworks.LeepartneredwithartistJackKirbytolaunchtheFantasticFour.Thecomicbookwasaninstanthit5leadtothedevelopmentofothersuperherocharacterssuchasIronManThorandSpider﹣Man. In1972Leespenttimepromotingthecompany.Whileintelevision6showtheMarvelcharacterslikeSpider﹣ManandtheHulkdid7goodachievingsuccessonthebigscreenproveddifficult.8wasnotuntilthe2000releaseofTheX﹣MenthatMarvel'ssuperheroesbecamepopularonthebigscreen. In2009theWaltDisneyCompanyacquiredMarvel9liftedupthesuperheroworldfurtherwithsummerblockbusterslikeTheAvengers.ThoughLeeisno10longwithushislarger﹣than﹣lifepersonalityfun﹣lovingwitandcharmwillberememberedforgenerationstocome.
九章算术是我国古代的数学名著体现了古代劳动人民的数学智慧其中第六章“均输”中有一竹节容量问题某教师根据这一问题的思想设计了如图所示的程序框图若输出m的值为67则输入a的值为
Dreamingofsummerpicnicsfilledwithfamilyandfun?We'vecomeupwith4ofthetoppicnicareasacrosstheUS. CumberlandIslandsGeorgia JustafewhourssouthofSavannahthisnationalseashoreisapicnicparadise.It'sanunspoiledplaceintheDeepSouthwithover50milesofhikingtrails小径.CoveredinSpanishmossthetrailsarelinedwithtreesandsinceit'sstillaruralareathestarslineupforaspectacularshowatnightandcreatestheperfecteveningstarlitpicnicopportunity. GiantParkChicago IfyouarelookingfordeliciousfoodinChicagogoforatasteofa20﹣daylake﹣frontfoodiefestivalthathappensinOctobereachyear.Grabaspotnearthefountaintoenjoyyourpicnicappreciatethecitysceneryandlakeviewsandrelaxwithfamilyandfriends.IfyouarethereonJuly4thbesuretoplanthedaytoincludethefireworksdisplayattheNavyPier. CranberryIslandsMaine Hereyou'llenjoynaturalpicnicswithislandviews.Theislandsareadelightfulgroupofislandsabout20minutesoffshorefromAcadiaNationalPark.Youcanvisittheislandsbyprivateboatorferry渡船service.Bringapicnicbasketalongfortherideasit'saromanticpicnicareatotakeyourspecialsomeoneorgoforafamilyoutingtovisittheislands. BigSurCalifornia ThePointLobosStateReserveisasmallgem.Besidesthecoastalwildlifetherearerareplantcommunitiesanduniquegeological地质的formations.It'sgoodtohaveapicnicthere.Werecommendbringingatelescopebecausemuchofthewildlifecanbeseenonlyatadistance. 1WhatareCumberlandIslandslike? A.TheyarejustnexttoSavannah. B.Theyhaven'tlosttheirnaturalness. C.TheyarealmostcoveredinSpanishmoss. D.Theyhaveaspectacularshoweverynight. 2Wherecanyouenjoyobservingwildlifewithatelescope? A.AttheNavyPier. B.IntheDeepSouth. C.AtAcadiaNationalPark. D.AtthePointLobosStateReserve. 3Whydoestheauthorwritethispassage? A.Tointroducesomepicnicareas. B.Tosharepersonalstoriesaboutpicnics. C.Totellreaderssomegoodwaystorelax. D.Toofferreaderstipsforwinterholiday. 4Wherecanwemostprobablyreadthispassage? A.Inapersonaldairy. B.Inasciencereport. C.Inatravelmagazine. D.Inageographytextbook.
若变量xy满足约束条件则x+2y的最大值是
如图四棱锥S-ABCD的底面ABCD是直角梯形AB∥CDAB⊥BCAB＝2BC＝2CD△SAD是正三角形． 1试在棱AB上找一点M使得BC∥平面SDM 2若平面SAD⊥ABCD在1的条件下试求二面角S-MD-A的正弦值．
AgroupofstudentsfromChina'sTibetAutonomousRegionsetoutfromLhasaonFridaytokickoffasportstourinBeijing. TheeightmiddleschoolstudentsfromDamxungCounty1locateinthenorthofLhasawillvisittheBird'sNestandWaterCube.Afterwardsthegroupwilltaketrainingclasseswithprofessionalfootball2coachfromSpain. Istartedplayingfootballinprimaryschoo1.NowI'malittlenervousbut3exciteaboutthejourney.It'smyfirsttime41eavemyhometownsaidsixteen﹣year﹣oldTeazinPhuntsok5addthattheplacehewantstovisitthemostinBeijingistheBird'sNest. Tenzinalongwith6hefellowstudentswasselectedfrommorethan60candidatesallof7arefromremoteregionsinTibet.ThetourtheyareabouttotakeisapartofFreeFootballforAll8projectlaunchedbySamaranchFoundationin2013.Inordertopromotefootballandthecountry'snewnationalfitnessprogramtheprojecthasorganizedfootballtrainingforyoungpeopleingrassrootsfootballleaguesacrossChina. SamaranchFoundation9foundin2012.Itisnamed10formerInternationalOlympicCommitteePresidentJuanAntonioSamaranch.
Squirrelsaren'tnaturalcitydwellers居民．In1986thesightofoneinatreenearNewYork'scityhallsosurprisedpassers﹣bythatanewspaperpublishedareportabouttheunusualvisitor． Aroundthattimethetree﹣dwellinganimalswerebeingsetfreeinAmerica'surbanareastocreatepocketsofpeaceandcalmlikethecountrysidesaysUniversityofPennsylvaniahistorianEtienneBensonwhostudiedourrelationshiptosquirrelsoverthecourseoffiveyears． FirsttheywereintroducedtoPhiladelphiathentoNewHavenBostonandNewYorkCity．Parkvisitorswereencouragedtofeedthemandsecurityguardsensuredtheirsafety．Inthe1910saleaderoftheBoyScoutsofAmericaanorganizationteachingboyspracticalskillssaidthatteachingchildrentofeedsquirrelscouldshowtherewardsoftreatingaweakercreaturewithsympathysaysBenson． Bytheearly20thcenturythoughAmericabegantoregretthefriendlinessithadshownsquirrels．Citieshadoncebeenfilledwithanimals﹣fromhorsespullinggoodstodairycows．Bythe1950sthoseworkinganimalshadbeenmovedtothecountryside．Petsandwildanimalssuchasbirdsandsquirrelswereallthatremainedoftheurbananimalkingdom． Beforelongpeople'senthusiasmforsquirrelsworeoffandtheystartedtoseethemasannoyances．Bythe1970smanyparksbannedfeedingthecreatures．Todayitisraretofindkidswiththeirparentsofferingfoodtosquirrelsunderatree．Andunfortunatelywithmoreandmorebuildingsbeingconstructedinthecityfewerinhabitable适宜栖息的areasareleftforthelittletree﹣dwellinganimals． WhatwouldbelostifthelastofthesecitydwellerswereforcedtoleaveIthinkthere'ssomethingconstructivetohaveotherlivingcreaturesinthecitythatarenothumansandnotpetsbutsharethelandwithussaysBenson．It'sagoodthingtoliveinalandscapewhereyouseeothercreaturesgoingaroundmakinglunch．It'sgoodforthesoul． 1What'sthepurposeofintroducingsquirrelstoPhiladelphiaD A．Toentertainparkvisitors． B．Tokeepthenaturalbalance． C．Toencouragekidstoprotectanimals． D．Tomaketheurbanlifemorepeaceful． 2WhatwastheBoyScoutsleader'sattitudetowardsfeedingsquirrelsC A．Disagreeable． B．Doubtful． C．Supportive． D．Uncaring． 3Whatmighthavehappenedtosquirrelsincitiesaroundthe1960sB A．Theymighthaveinhabitedmorehomes． B．Theymighthavebeguntogooutoffavor． C．Theymighthavebeenintroducedtomorecities． D．Theymighthavebeenmovedtothecountryside． 4WhatdoesBensonsuggestinthelastparagraphC A．Squirrelslivingincitiesareannoying． B．Feedingsquirrelsshouldbediscouraged． C．Squirrelsshouldbeallowedtoliveincities． D．Itispossibleforpeopletokeepsquirrelsaspets．
孙悟空猪八戒沙和尚三人中有一个人在唐僧不在时偷吃了干粮后来唐僧问谁偷吃了干粮孙悟空说是猪八戒猪八戒说不是他沙和尚说也不是他．他们三人中只有一个说了真话那么偷吃了干粮的是．
已知函数fx对任意的x∈R都有2019fx+f'x＜0且f1＝e-2019那么不等式fx＞e-2019x的解集为．
Adoverestedonatelephonewire.Readyfortakeoffitraisesitswingsspringsintotheairandflapsaway.Thisseriesofactionsissocommonthatyouprobablydonotpayitmuchattention.ButUniversityofManchesterbioinechanicalengineerBenParslewdoes.Heistryingtodesignrobotsthatcanjumplikebirds. Mostconventionalrobotsrollaroundonwheelslimitingmobility.ThereisaneedformoreagilerobotsthatcanjumpoverobstaclesinmessyenvironmentsParslewsays.TodesignsuchamachineheturnedtonatureBirdsarereallygoodjumpershenotes. Thetroubleiswhenbirdsstarttotakeofftheyleansofarforwardthattheyshouldtipoverandfallontotheirbeaks喙.Yetthatdoesnothappen.Parslewandhisteamusedcomputermodelingtodiscoverhowbirdsavoidthisfate.Theydiscoveredthatbirdstwisttheirbodiesslightlytowardsthebackwhileacceleratingintoajump.Theyalsohaveflexiblelegsandtoejointswhichpreventthemfromtakingoffbrieflyandimmediatelycrashingintotheground.TheresultwerepublishedlastOctoberinRoyalSocietyOpenScience. Parslewthinksengineerscanusethisinformationtodesignrobotsthatcannotonlyjumpwellbutalsolaunchintoflightmore.efficiently.UniversityofSouthernCaliforniabiomechanistMichaelHabibwhowasnotinvolvedinthestudysaysspringsandlevers杠杆enablemorerapidacceleration﹣thanwheelsdo.Andmanyanimalsaremastersofspringsandlevers. IfyoucanunderstandhowthatworksHabibaddsyoucanbuildarobotthat'sgoodatrunningaroundandgoodatflyinganditwillalsobegoodattakingoffsuddenlyinallkindsofconditionsandlandingonadime.Parslewisnowdesigningsucharobotasanalternativetowheeledroversforexploringotherplanets. 1WhatisrightaboutthedovementionedinParagraph1? A.Ittakesoffverybeautifully. B.Itcatcheseveryone'sattention. C.ItgivesBenParslewinspiration. D.ItraisesBenParslew'scuriosity. 2Whatcanwe﹣inferaboutthetraditionalrobots? A.Theycan'tjumpoverbarriers. B.Theycanonlymoveinonedirection. C.Theycan'tdetectbarriersbeforethem. D.Theycan'tadapttocomplexenvironments. 3Howdoesabirdavoidfallingwhentakingoff? A.Bygettingridofgravity. B.Byflappingitswingshard. C.Byspinningitsbodybackward. D.Byjumpingintotheairquickly. 4Whatisthemainideaofthetext? A.Birdsprovideinspiration.forhumans. B.Newrobotsthatcanjumphavebeencreated. C.Thedevelopmentofrobotsbenefitsspaceexp D.Studyingbirds'jumpinghelpsscientistbuildbetterrobots.
ChineseartisavisualartthatispracticedinChinaorbyChineseartists.TheChineseartofoverseasChinesecanalsobeviewed1partofChineseartbecauseitisbasedonChineseculture. Earlystoneageartdatesbackto10000BCmostly2consistofsimplepotteryandsculptures.AfterthatChineseartlikeChinesehistoryistypicallyclassifiedbydynasty3probablylastedseveralhundredyears. Chinesearthastheoldestcontinuoustraditionintheworld.SincetheRenaissancethedecorativeartshavebeen4extremeimportantinChineseartespeciallyinChineseceramics陶器. Differentformsofarthavechangedundertheinfluenceofgreatphilosophers5religionfiguresandevenpoliticalfigures.EarlyChinesepoetry6influencebytheBookofSongsandtheChinesepoetandstatesmanQuYuan. Chinesepaintingbecameahighly7appreciateartincludingawidevarietyof8stylesuchasMingDynastypainting.EarlyChinesemusicwasbasedonpercussion打击乐器whichlatergavewaytostringedinstruments.IntheHandynastypapercuttingbecame9newartformaftertheinventionofpaper.Chineseoperawouldalsobeintroducedandbranchedregionallyinadditiontoother10performformatssuchasvarietyshows.
已知椭圆的离心率为一个焦点在直线上直线l与椭圆交于PQ两点其中直线OP的斜率为k1直线OQ的斜率为k2． 1求椭圆方程 2若试问△OPQ的面积是否为定值若是求出这个定值若不是请说明理由．
Launchedin2015andduetoendin2020theSkillsforReconstructionprojectteachesNepalisinearthquake﹣hitareashowtobuilddisaster﹣resilienthouses.Theaimistohelpeasethecountry'slabourshortagewhilealsoarmingparticipantswithexperiencetheycalllaterusetofindjobsinconstruction. ThetrainingprojectisjointlyfinancedbytheNepalesegovernmentandtheSwissDevelopment.Sinceitslaunchithastrainedalmost9000peopleinthe14districtsmostseverelyaffectedbytheearthquakeandmostvulnerabletofutureclimatedisasters. Traineeshaverebuiltmorethan3000housesin10ofthosedistricts.Intheotherfourlimitedaccesstoremoteareasandashortageofskilledlabourerstorunthetrainingprogrammeshasstalledreconstruction. ManyofthenewhomeshavebeenbuiltusinghousinggrantsfromtheNationalReconstructionAuthority.InMakawanpurdistrictabout33250familiesarequalifiedtoreceivegrantsof﹩3000eachpaidoutinthreeshares. MostofthehousesdestroyedbytheearthquakeacrossruralNepalweremadeusingtraditionalmaterialsofwoodandstonewithnopillars柱子forsupport.Thedesignsprescribed规定bytheNRAfornewbuildingsaremorelikelytowithstandearthquakes.Builderscallchoosefromarangeofmaterialstechniquesanddesigns﹣fromatwo﹣storeystructuremadeofsteelandbrickstoatwo﹣roomhomeconstructedfromrubble.mudandwire. Peopleherehavemostlyfollowedtheone﹣ortwo﹣roommodelhomesAerisaid.Anyonelivingclosetoarivermustrebuildatleast20metresawayfromtheriverbanktoavoidfloodwatersreachingtheirhomesduringrainyseason.SomefamiliesinremoteareasthatthemasontrainingprogrammecouldnotreachhaverebuilttheirhomeswithoutfollowingtheNRA'sbuildingcodesandcriteria. 1Whatbenefitcantraineesgetfromthetrainingproject? A.Helpthemtofindjobs. B.Makealargesumofmoney. C.Avoidbeinginjuredinearthquakes. D.Ensurethemtoliveacomfortablelife. 2WhatdoestheunderlinedwordstalledinPara.3mean? A.Improved. B.Renewed. C.Stopped. D.Sped. 3WhatweremostoftheruralNepal'shousesdestroyedmadeof? A.Woodandstone. B.Woodandpillars. C.Steelandbricks. D.Mudandwire. 4WhatisAeri'sattitudetotheone﹣ortwo﹣roommodelhomes? A.Favourable. B.Disapproving. C.Unclear. D.Doubtful.
Haveyoueverheardthetermdarkrideandwondered1whatitmeantHowaboutflatrideLet'sexploresomeofthemorecommon2typestypeofrides． Adarkrideisanindustrytermforanyamusementparkorthemeparkridethatusesvehiclestosendpassengersintoanindoorenvironmentandthrough3aseriesofscenes．Ridevehiclestakemanyforms4includingincludecarsonatracktracklessvehiclesandboats5that/whichfloatinachannelofwater．Somedarkridesattempttotellastorywhileothersarejustacollectionofinterestingscenes． Aflatridereferstoattractionsatamusementparkscarnivalsfairsandthemeparksthattypicallyspinaround． They6usuallyusualincludeacircularplatformandareplacedontheground．Thetermisusedtorefertoalargenumberofrides．7Dependingdependontheirspeedandotherfeaturestheymayormaynotbeconsideredthrillrides．Generallykiddierides8areintendedintendforyoungriders．Morethrillingflatridesthatincludehighspeedsintheamusementindustryarecalledspin﹣and﹣spewspin﹣and﹣pukeorwhirl﹣andhurlrides． Amotionsimulatorrideusesseatsthatmovewithpoint﹣of﹣viewmediaprojectedontoascreen9toprovideprovideviewerswiththeillusion错觉thattheyaremovingandphysicallytakingpartintheaction．Mostmotionsimulatorridesarepresentedintheatersofvarioussizes．Althoughviewersnevermovemorethanafewinchesinany10directiondirecttheycanfeelasiftheyarespeedingwildlyandfree﹣fallingetc．
若z＝则复数＝
在一次连环交通事故中只有一个人需要负主要责任但在警察询问时甲说“主要责任在乙”乙说“丙应负主要责任”丙说“甲说的对”丁说“反正我没有责任”四人中只有一个人说的是真话则该事故中需要负主要责任的人是
ThebestsummercampsforteensinNYC AsphaltGreenSummerDayCamp 555E90thStNewYorkJune27﹣Aug16pricesstartingat﹩4150 Youcanchoosebetweenaswimsportsorartscampwithexpertinstructors.Swimmerscanspendtheirtimewithendlesspooltimeyoungathleteswillbeintheirnaturalenvironmentastheyplaybasketballbaseballtennisandotherteamsportsandcreativescanexpressthemselvesinmanymediaincludingthecircusartsandfilm. TheNaturePlaceDayCamp 285HungryHollowRdChestnutRidgeJuly1﹣Aug9variousprices The200﹣acrecampisperfectforexploringthegreatoutdoors.Kidsgettheirhandsdirtyinthefarmlandgardensfieldsandponds.Besidestheymastervaluablefarmskillssuchasharvestingcropsandtakingcareofcutelittlechickens.FarmandGardenDaysofferyourchildrenevenmoreopportunitiestohelpwiththeharvestandanimalwork. CenterforArchitectureCamp 536LaGuardiaP1NewYorkJune24﹣Aug23﹩650/week YoungNewYorkerswhoneverstoptobeamazedbyskyscraperscanimagineandbuildtheirownmodels﹣afterthey'velearnedhowtohandlethedesignchallengesofreallytallstructures.Similarfive﹣dayprogramsexistfortreehousesandbridgesandotherofferingsallowfuturearchitectstostudydigitaldesignusing3﹣Dcomputermodelingorold﹣schoolfreehanddrawing. IndependentLakeCamp 70ClarkRdThompsonJune23﹣Aug25﹩3150﹣﹩4895 IndependentLakeCampisallaboutkidsdoingintheirway.Itcouldalsomeanbreakingawayfromthegrouptoridetherailsintheskateparkorholdontightonthegiantswing.Activitiesevenincludemagicsdigitalartslikebuildingyourowncomputerormakingyourowngameandcircusarts.Theatmospherehereisrelaxed. 1Whichcampissuitableforkidslovingharvestcrops? A.AsphaltGreenSummerDayCamp. B.TheNaturePlaceDayCamp. C.CenterforArchitectureCamp. D.IndependentLakeCamp. 2WhatistheprimaryfocusforCenterforArchitectureCamp? A.Models. B.Treehouses. C.Structures. D.Drawing. 3WhatisuniqueaboutIndependentLakeCamp? A.Itwinstheattentionofkids. B.Theparkiscoolandrelaxed. C.Kidscandothingsintheirownway. D.Kidscantakeupswimming.
MakingTravelArrangements Getplaneticketsifyou'reflying.Especiallyifyou'retravelinginternationallyyourplaneticketsmaybethemostexpensivepartofyourtrip.1.Soyouknowexactlywhenyou'llbearrivingandhowlongyou'llbestaying.Bemindfuloftimezonesifyou'retravelingalongerdistance.Thearrivalordeparturetimeslistedreflectthelocaltimeatthatparticularairport. Haveyourvehicleservicedifyou'redriving.Beforeyougoonaroadtripgettheoilchangedinyourvehicleandhaveitinspected.Completeanynecessaryrepairs.2. Makecopiesofallimportantdocuments.Copythefrontandbackofidentificationandinsurancedocuments.Ifyoulosetheoriginalsyoucanusethecopiestore﹣establishyouridentityandgetbackhome.3 Gettravelinsuranceforlongerormoreexpensivetrips.Ifyouhavehomeowner'sorrenter'sinsuranceyourpolicywilllikelycoverlostordamagedbelongings.Youcanalsopurchaseadditionalcoveragetocoverexpensesyoumaypayastheresultofacancelledordelayedflight.4.Howeveryoumayhavetouseyourcreditcardtopurchaseplaneticketsorreserveaccommodationstogetthecoverage. 5.Ifyou'retravelingtoanothercountryyou'lllikelyneedapassport.Applyseveralmonthsinadvancetomakesureyouhaveitforyourtrip.Totraveltosomecountriesyoumayalsoneedatouristvisa. A.Takingplanescostsmuch B.Getyourplaneticketsfirst C.Besuretocarryyourpassportandvisa D.Applyforapassportorvisaifnecessary E.Creditcardcompaniesoftenprovidetravelinsurance F.Soyouknowthatyourvehicleisintopconditionforthetrip G.Makecopiesofanymedicaldocumentationorprescriptionsaswell
Thefirstyearofcollegeisoneofthebestandthemostinterestingperiodsoflife.1Ontheonehanditcanbestressingtoleaveyourtownandstartcommunicatingwiththepeopleyoudon'tknowbutwhenyougetusedtotheatmosphereyou'llreallyappreciateandlovethetimespentincollege. 1.2 There'sabigamountofinformationyou'vegottoknow.Youmightunderstandhowtoregisterforclasseswhatthenamesofyourprofessorsareorhowtodooneoranothertaskinaproperway.Collegeisfullofstudentswhoareformerfreshmen.Theycangiveyouahelpinghandifyoudon'tknowsomething. 2.Manageyourtime Timemanagementisanextremelyimportantskillthatwillcomeinhandyineverydayusagefortherestofyourlife.Yourfuture﹣successdependsonthewayyouspendyourfreetime.Atcollegeit'snecessarytofindtimeforstudiesandforhavingfun.Oneofthebestwaystomanageyourtimeduringthefirstyearistomakeaschedule3 3.Usethecampusstudyresources. Manystudentscomplainaboutthelackofliteratureandaboutthehighpricesoftextbooks.4Therearemanydatabaseslabsandlibrarieswhichcanhelpyouexpandyourmind. 4.Joinstudentorganizations 5Differentsocialandsportorganizationscanhelpyouexpressyourselfanddiscoveryourinterests.Asastudentofthefirstcourseyouneedtomakefriendsandgetinvolvedindifferentstudentcommunities.Yourmembershipwillimproveyourreputationincollegeandfillyourbusystudent'slifewithnewemotionsandadventures. A.Don'tbeafraidtoaskforhelp. B.Don'tbeafraidtoleaveyourcomfortzone. C.Itwillhelpyousucceedandreachallgoalsyouneed. D.Whynotusetheresourcesofferedbyacollegeyou'restudyingat? E.Youneedtorememberthatyouaretheonlywho'sresponsibleforyourstudy. F.Nowadaysallcollegecampusesofferyouabigvarietyofstudentorganizations. G.Youshouldbestrongenoughtostepintothenextstageofyourlifewithoutdoubtsandhesitations.
Calligraphyisavisualart1relatetowriting.Itisthedesignandexecutionoflettering withabroadtipinstrumentbrushorotherwritinginstruments. InChinacalligraphyisreferredto2shufa.Chinesecalligraphyhas3longtraditionandistodayregardedasoneoftheartsinthecountries4itispracticed.Chinesecalligraphy5focusnotonlyonmethodsofwritingbutalsooncultivatingone'scharacter. Chinesecalligraphyisafarmofaestheticallypleasingwriting.ThistypeofexpressionhasbeenwidelypracticedinChinaandhasbeen6generalheldinhighesteemacrossEastAsia. Calligraphy7considerasoneofthefourbestfriendsofancientChineseliteratialongwithplayingstringedmusicalinstrumenttheboardgamegoandpainting.Therearesomegeneralstandardizationsofthe8varystylesofcalligraphyinthistradition. Chinesecalligraphyandinkandwashpaintingarecloselyrelatedtheyareaccomplished9usesimilartoolsandtechniquesandhavealonghistoryofsharedartistry.DistinguishingfeaturesofChinesepaintingandcalligraphyincludeanemphasisonmotionchargedwithdynamiclife.Calligraphyhasalsoledtothedevelopmentofmany10formofartinChinaincludingsealcarvingornatepaperweightsandinkstones.
在直角坐标系中直线l的参数方程为在以坐标原点为极点x轴正半轴为极轴的极坐标系中曲线C的极坐标方程为 1求直线l的普通方程和曲线C的直角坐标方程 2求曲线C上的点到直线l的距离的最小值．
Withatougheconomyit'sdifficulttomeetouremployees'expectationofsalaryincreases.1Wellherearefourimportantfactorsthathelpkeepemployeesmotivatedinadditiontomoney. Thefirstoneisrecognition.2Examplesincludetakingsomeonetolunchandlettingthemknowhowmuchyouvaluetheirperformanceandhowyouthankthembecausethey'reloyalpubliclyrecognizingsomeone'sperformancewithdetailsofwhattheydidandpresentingcertificatesofrecognitionforextraordinarycontributionstothebusinessandtheorganization. 3Ifyoucan'taffordtogiveeverydeservingemployeearaiseinvitethemtoapartytosimplycelebratetheirgoodworkandtellthemhowmuchyouappreciatetheirhardworkandloyalty.Askthemtohelpyouachieveyourbusinessgoalssothatnexttimeyoucanrewardtheminbetterways. Anotheroneismotivationalclimate.Takealookaroundattheworkenvironmentanddowhateveryoucantomakeitamorepleasantplace.Redecorationbetterworkspacesandworkingenvironmentthatisn'texpensivewillbeappreciatedbythosewhospend8﹣10hoursadayworkingthere.4 Thelastbutmostimportantfactorthatcanmotivateemployeesistrust.It'simportanttobuildtrustinallyourworkrelationships.5Takeaninterestintheirfamiliestheirhobbiesandtheirdevelopment.Treatpeoplewithrespect.Thenextoneiscelebrations. A.Thesecondoneispersuasion. B.Conductteamdiscussionsonwaystoincreasebusinessprofits. C.Appreciatingaperson'sstrongcontributioncanmakeadifference. D.Toachievethisspendtimewithyouremployeesandshowyourcareaboutthem. E.Ifyouaren'tsurewhattodoaskyouremployeeswhatthey'dlikeintermsofit. F.Howcanwemotivatetheminotherwaystokeepthemfromleavingthecompany?
Belowyouwillfindaprofileofeachgapyearprogram.Ifthereisaspecificprogramyouareinterestedinoraquestionyouhaveregardingtheseprogramspleasefeelfreetocontactthemdirectly. YouthInternational Since1997YouthInternationalhasbeenprovidingmanypeoplewiththemostexcitingandeducationalexperienceoftheirlife.Itisalearningprogramthatcombinesinternationaltravelinter﹣culturalexchangehomestaysvolunteercommunityserviceworkandoutdooradventures. Phone720﹣270﹣3323Carpe DiemEducation ThroughvolunteerservicetravelandculturalexchangestudentsofCarpeDiemEducationreceiveapersonalinsightintothemselvesandtheircultures.Wespecializeinguidingsummerandsemesterprogramsforhighschoolstudents.Eachcourseiscarefullycraftedtodevelopleadershipandself﹣awarenesswithinourstudentswhoreturnhomebetterpreparedtobeleadersinthoughtandaction. Phone503﹣285﹣1800 CenterforInterimPrograms Foundedin1980CenterforInterimProgramsisthefirstindependentgap﹣yearorganizationinAmerica.Basedonstudents'interestsandbudgetourexperiencedteachershelpmakeindividualcoursechoicesincludinglowcostvolunteeroptionslanguageprogramsresearchtripsandsoon.Wearecommittedtohelpingstudentsfindmoreexperiencesofformaleducationandwork. Phone413﹣585﹣0980EF GapYear EFGapYearoffersstudentstheabilitytoexploreseveralcountrieswhereyouwilllearnalanguagevolunteerforagoodcausegaininternationalworkexperience.Choosebetweena12﹣weeksemesteror26﹣weekacademicyear.Youcanthenpersonalizeyourprogramtomeetyourlearninggoalsandinterestsbydecidingwherewhenand﹣howyouwishtostudyonyourown.Ourwell﹣structuredcurriculumevenallowsyoutoplaceoutofcollege﹣levelclassesandearnadvancedcreditstowardgraduation. Phone800﹣726﹣9746 1Whichphonenumbercanyoudialifyouwanttoimproveyourleadership? A.720﹣270﹣3323. B.503﹣285﹣1800. C.413﹣585﹣0980. D.800﹣726﹣9746. 2WhatisEFGapYear'suniquefeature? A.Itsreasonablefee. B.Itsexperiencedteachers. C.Itsflexiblestudytime. D.Itsdiversecurriculumchoices. 3Whatdothefourprogramshaveincommon? A.Theypayattentiontovolunteerservicework. B.Theycombineeducationwithhomestays. C.Theymainlyoffercross﹣culturaleducation. D.Theyraisestudents'interestinadventure.
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