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如图所示，有一足够长的光滑平行金属导轨折成倾斜和水平两部分，倾斜部分导轨平面与水平面的夹角为θ＝300，水平和倾斜部分均处在匀强磁场中，磁感应强度为B，水平部分磁场方向竖直向下，倾斜部分磁场方向垂直...
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高三下学期物理《》真题及答案
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如图所示两根足够长的平行金属导轨由倾斜和水平两部分平滑连接组成倾斜部分的倾角θ=45°水平部分处于方
有一Π形光滑金属导轨倾斜放置两段平行轨道相距L.轨道所在平面与水平面间夹角为a有一垂直于轨道平面向上
如图所示金属棒a从高为h处由静止沿光滑的弧形导轨下滑进入光滑导轨的水平部分导轨的水平部分处于竖直向下
⑴如图所示平行金属导轨与水平轨道相连接轨道光滑且足够长轨道间宽为L.轨道电阻可忽略轨道的水平部分有竖
如图B-4所示上下不等宽的平行金属导轨的EF和GH两部分导轨间的距离为2LIJ和MN两部分导轨间的距
2mg
3mg
4mg
mg
如图所示两平行导轨间距L.＝0.1m足够长光滑的倾斜部分和粗糙的水平部分圆滑连接倾斜部分与水平面的夹
如图1所示水平放置的光滑金属导轨由宽窄两部分组成宽部分的宽度是窄部分的两倍有一范围足够大的匀强磁场垂
如图所示金属棒a从高为h处由静止沿光滑的弧形导轨下滑进入光滑导轨的水平部分导轨的水平部分处于竖直向下
如图所示金属棒a从高为h处由静止沿光滑的弧形导轨下滑进入光滑导轨的水平部分导轨的水平部分处于竖直向下
光滑的水平金属导轨如图其左右两部分宽度之比为1∶2导轨间有大小相等但左右两部分方向相反的匀强磁场.两
如图所示两根平行金属导轨相距L.上端接有直流电源电源电动势为E.内阻为r导轨的倾斜部分与水平面成θ角
如图甲所示一足够长阻值不计的光滑平行金属导轨MNPQ之间的距离L.＝1.0mNQ两端连接阻值R.＝1
如图所示上下不等宽的平行金属导轨的EF和GH两部分导轨间的距离为2L.IJ和MN两部分导轨间的距离为
2mg
3mg
4mg
mg
如图所示两平行导轨间距L.=0.1m足够长光滑的倾斜部分和粗糙的水平部分圆滑连接倾斜部分与水平面的夹
如图所示两根质量均为m=2kg的金属棒垂直地放在光滑的水平导轨上左右两部分导轨间距之比为1∶2导轨间
10分两根平行光滑金属导轨MN和PQ水平放置其间距为d=0.6m磁感应强度为B.=0.5T的匀强磁场
如图所示两根平行金属导轨相距L.上端接有直流电源电源电动势为E.内阻为r导轨的倾斜部分与水平面成θ角
如图所示两根弯折的光滑金属棒ABC和DEF固定成正对平行的导轨其中AB和DE部分水平倾斜的BC和EF
最后两棒匀速运动
cd棒的速度始终大于ab棒的速度
cd棒的加速度一直减小
回路中电流先增大后不变
如图所示两平行导轨间距L.=0.1m足够长光滑的倾斜部分和粗糙的水平部分圆滑连接倾斜部分与水平面夹角
辽宁省沈阳市东北育才学校2017高三第九次模拟如图所示间距为L.的平行且足够长的光滑导轨由两部分组成
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Howtohelpawheelchairuserintoachair Ifyou'relookingaftersomeonewhousesawheelchairknowingthecorrectwaytoassisthiminDtoandoutofhischaircanbequiteimportant．1Soit'snecessarytounderstandhowtolendahandsafelybeforeyouattempttodoso． 1．Preparethechair． It'scrucialtoensurethatthechairisreadyforthepersontositinbeforeyoubegintomovehim．Nevertrytoadjustthechairwhenyou'realreadybearingaperson'sweight．Insteadensurethatthechairisintherightpositionbeforeyoustart．2 2．Liftsafely． Beforeyoucanhelpawheelchairuserintoachairyouneedtobeawareofseveralfactorsaswellasthecorrectwaytoliftthechairuser．Makesureyouknowhowheavyyourfriendorfamilymemberisandthatyou'restrongenoughtolifthimtositsafelyinthechair．3Yourclothingandfootwearisalsoimportant．Ensurethereisnothingyou'rewearingthatcouldcatchandthatyourshoesallowcompletestability． 3．4 Loweryourfriendorfamilymemberintothewheelchairslowlyandsteadilymakingsuretheyarefullyseatedinthechair．Iftheyareabletostandandlowerthemselvesintothechairstandbehinditandholdontothehandlestomakesureitdoesn'tmove．5Beforemovingthewheelchairaskthemtoplacetheirhandsintheirlapormoreimportantlyawayfromthewheelssothattheycanfeelcomfortable． Aboveallcheckthatthepersonyouareassistingiscalmandrelaxedandhappytoreceivehelp． A．Makethemcomfortable． B．Rememberloleavethewheelchairbehind． C．Youshouldheinanareawithnoobstaclesintheway． D．Makesureyoucanhaveafreetalkwiththewheelchairuser． E．Notknowingtherighttechniquescanresultininjurytothewheelchairuser． F．Oncetheyareseatedswingthefootrestsbackintoplacemindingtheirlegs． G．Mostimportantlymakesurethewheelchairbrakesareonandthatthechairistotallystable．
在三棱柱ABC﹣A1B1C1中AC＝BC＝2∠ACB＝120°D为A1B1的中点． 1证明A1C∥平面BC1D 2若A1A＝A1C点A1在平面ABC的射影在AC上且BC与平面BC1D所成角的正弦值为求三棱柱ABC﹣A1B1C1的高．
在数列{an}中a2＝5a5＝2且2an+1﹣an+2＝ann∈N*则|a1|+|a2|+……+|a10|的值是
已知函数fx＝则flog25＝
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．ItwasattheGreenStorethatIfindabrokenrockingchairandputitinbackofmytruck．Theseatwassplitintotwofromfronttoback．Otherthanthatitwasinexcellentlycondition．IthoughtIshouldrepairitsothatbythefollowingdayitwouldbesogoodasanewone．BySundayafternoonthegluehadsetandaftertwocoatofbrightwhitepaintthechairwasofperfect．IwasexcitingbecauseIwasgoingtosurprisemywife．Wewerenewparenttoabeautifulbabyboy．Ournewbabylovedtoberockedbutwedidn5thaveaproperrockingchair．Thischairwasbeautifulandhiswifewasveryhappywithit．
假段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\划掉． 修改在错的词下画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． Squaredancinghasbeenmoreandmorepopularwiththeelderlyastheirlivingconditionsimprove．Mostpeoplethoughtitcanhelppeopletakeregularlyexerciseandstrengthentheirfitness．Besidesitprovidespeoplemorechancestotakeactivityoutdoors．Howeversomepeoplearguethatthemusicisverynoisythatdisturbsthesurroundingcitizens'normallife．Alsobeexposedtosuchloudnoisemaydoaharmtotheirhealthinthelongrun． Inmyopinionsquaredancingisagoodformofexercisesodancersshouldtakeourneighbors'needsintoconsideration．Iftheychoosearighttimeandturndownthemusicitwillcausefewertroubleforothers．
设全集U＝R集合A＝{x|log2x≤1}B＝{x|x2+x﹣2≥0}则A∩∁UB＝
若xy满足则z＝y﹣2x的最大值为
1Suzanwantstobeanactressshecanchoose． A．CourseA B．CourseB C．CourseD D．CourseE 2CourseCisfitforthestudentswhomight． A．dealwiththenumbers B．workwiththedisabled C．runabusinessorganization D．designandconstructbuildings 3IfDavidchoosesCourseFhemightbeastudentwiththecareerinterestin． A．advertising B．politics C．nursing D．management 4Wherecanweprobablyfindthepassage A．Inacityguidebook． B．Inasciencejournal． C．Onaschoolwebsite． D．Fromanewsreport．
Accordingtolegendayoungmanwhilewanderingthedesertcameacrossaspringofdeliciouscrystal﹣clearwater．The1wassosweethefilledhisleathercontainersohecouldbringsomebacktoatribalelderwhohadbeenhis2． Afterafour﹣dayjourneyhe3thewatertotheoldmanwhotookadeepdrinksmiledwarmlyand4hisstudentlavishly浪费地forthesweetwater．Theyoungmanreturnedtohiswitha5heart． Latertheteacherletanotherstudent6thewater．Hespatitoutsayingitwas7．Itapparentlyhadbecomestale不新鲜的becauseoftheold8container．Thestudent9histeacherMasterthewaterwas10．Whydidyou11tolikeitTheteacherrepliedYouonlytastedthewaterItastedthe12．Thewaterwassimplythecontainerforangetofloving﹣kindnessand13couldbesweeter．Ithinkweunderstandthislessonbestwhenwereceive14giftsoflovefromyoungchildren．Whetherit'sanuglyplateorabraceletthenaturalandproper15isappreciationandexpressed16becausewelovetheideawithinthegift． Gratitudedoesn'talwayscome17．Unfortunatelymostchildrenandmanyadults18onlythethinggivenratherthanthefeelingembodied被体现init．Weshouldremindourselvesand19ourchildrenaboutthebeautyandpurityoffeelingsandexpressionsofgratitude．20giftsfromtheheartarereallygiftsoftheheart． 1A．desert B．voice C．spring D．water 2A．master B．teacher C．relative D．friend 3A．took B．presented C．show D．delivered 4A．thanked B．nodded C．laughed D．joked 5A．light B．heavy C．happy D．broken 6A．throw B．pour C．taste D．bring 7A．tasty B．bitter C．hot D．awful 8A．leather B．rubber C．metal D．firm 9A．asked B．added C．challenged D．doubted 10A．fragrant B．delicious C．smelly D．bitter 11A．have B．pretend C．happen D．intend 12A．gift B．meaning C．feeling D．drink 13A．none B．everything C．seldom D．nothing 14A．innocent B．precious C．guilty D．priceless 15A．demand B．response C．comment D．problem 16A．thankfulness B．smile C．laughter D．praise 17A．firstly B．friendly C．immediately D．naturally 18A．ignore B．value C．stress D．forget 19A．tell B．bring C．teach D．send 20A．Asaresult B．Inaword C．Afterall D．Inthemeantime
PizzaisaprettycommontreatbutwherediditstartHerearethreethingsyouprobablydon'tknowaboutpizza． 1Pizza'sOriginsAreHalf﹣Baked． TheNeapolitansinItalyareproudofsayingtheyinventedpizzabutit'sprobablymoreaccuratetosaytheyperfectedit．Theideaofputtingtoppingsonaflatbreadandbakingitstartedinthe6thcenturyB．C．ButthepeopleofNapleswerethefirsttoputthetomatoonaflatbreadinthe16thcentury．Fromitsstartpizzawasthefoodforthepoorasitwascheapfillingandeasytoeatontherun．InItalianthewordpizzareferstoanythingthatismadeandthenpressedflat． 2PizzaMargheritaIsNotExactlyaSymbolofItaly． Itissaidthatonedayin1889alocalbakernamedRaffaeleEspositocreatedthreepizzasforQueenMargheritawhenshewasonatourofItaly．ThequeenlovedtheversionthathadthetomatobasilandmozzarellacheeseanditjusthappenedtomatchthecolorsoftheItalianflag．SoEspositonamedthepizzaafterher． ButScottWienerpointsoutthatItalywasunifiedinnameonlyin1889soitwasunlikelyanyNeapolitanbakerwouldwanttocelebratetheNorthernconquerorFurthertheletterofgratitudeforthepizzafromtheroyalhouseholdthatPizzeriaBrandidisplaysappearstobeafakeandmayjusthavebeenamarketingstrategy． 3HawaiianPizzaInventedbyaCanadian． SamPanopoulosfromGreeceoriginallymovedtoCanadaattheageof20．In1962hedecidedtoputsomehamandpineappleonapizzaatoneofhisrestaurantsinOntario． WejustdiditforfuntoseehowitwasgoingtotastehetoldtheBBCin2017．PanopoulosnamedittheHawaiianpizzaafterthebrandofthecannedpineappleheused．Themixtureofsweetandsavorytoppingsbecamepopularwithacertainpartofthepizza﹣lovingpublic．Theinventordiedin2017． 1Whowaspizzafirstmadefor A．Peoplewhowereverybusy． B．Peoplewhowererunningaway． C．Thepoorpeoplewhocouldaffordit． D．Soldiers． 2WhatisPizzeriaBrandi'spurposeofdisplayingtheletter A．ToshowhonorforQueenMargherita． B．Tohatchamarketingplot． C．Toprovethepizza'srelationwiththeroyalfamily． D．TotelltheworldPizzaMargheritaisexactlyasymbolofItaly． 3ThenameoftheHawaiianpizzacamefrom． A．anotherbrandoffood B．aCanadianrestaurant C．thefounder'sowninterest D．itsuniqueHawaiianflavor
数列{an}的前n项和为Sn且Sn＝3n﹣1n∈N*． 1求数列{an}的通项an 2求数列{2n﹣1an}的前n项和Tn
假定你是李华近期你市的人民剧院将上演著名京剧霸王别姬FarewellMyConcubine你恰好有两张票．请给在你市学习汉语的美国好友Jeremy写封邮件邀他一同前往观看． 内容包括1．演出时间地点 2．演出内容 注意1．词数100左右 2．可以适当增加细节以使行文连贯．
A OnceIwasplayinginthewoodswhentheskystartedtoturndarkandthewindstartedtoblow．Isawabigblackcloud1movetowardsme．SuddenlyIfelttherainhittingmyface!Actuallyitwaspouring!ThenIsawlightninginthesky．AndlaterBOOM!!!Aloudclapofthunder!ThenIsawalittleoldhutandraninside．Itsmelledawfulandthewallswereshakingbutitwas2goodthannothing!Outsidethewindwashowlingandthingswereflyingaround．Ijuststoodinthecornercoldandscared．3luckymydadcameandfoundme．Iwassafe! B LiBaiwasaChinesepoetpraisedfromhisowndaytothepresentasaromanticfigure4tooktraditionalpoeticformstonewheights．Thirty﹣fourofhispoemsareincludedinThreeHundredTangPoems．5heearlypoetrytookplaceinthegoldenageofTangdynasty．ThisallchangedsuddenlywhenallofnorthernChina6destroybywar．Fortunatelymanyofhispoems7surviveeversinceenjoyinglastingpopularityinChinaandelsewhere． C TheChineseLunar月球ExplorationProgramisdesignedtobeconductedinthreestagesThefirstissimplyreachinglunarorbit轨道atask8completebyChang'e1in2007andChang'e2in2010．Thesecondis9landontheMoonasChang'e3didin2013andChang'e4in2019．ThethirdoneiscollectinglunarsamplesandsendingthemtoEarthataskforthefutureChang'e5andChang'e6missions．It10beChina'sfirstsamplereturnmissioninDecember2019．
若抛物线x2＝2pyp＞0在点12处的切线也与圆x2+y2﹣2x+2y+2﹣a＝0相切则实数a的值为．
FreeEntrytoPalaceofVersailles﹣Save﹩18! ThePalaceofVersaillesisoneofthelargestandmostsplendidcastlesintheworld．Havingaround2143windows1252fireplacesand67staircasesthecastleisoneofthemostvisitedattractionsinFrance． Asafineexampleof18th﹣eenturyFrenchartthishistoricbuilding‘hasbeenonUNESCO'sWorldHeritage遗产Listfor30years． AtfirstitjustuhuntinghousebuiltbyLouisVIII．ButLouisXIVchosethesitetobuildthepalaceweknowtodaythesymbolofroyalabsolutism专权专治andclassicalseatofpowerin1789butgotroleinthe19thcenturyastheMuseumoftheHistoryofFrancewhichwasfoundedwhenLouisPhilippebecamethekingin1830． Thishistoriccastlewithitsbeautifularchitectureandgardensandlonghistoryisa．must﹣visitsightonasightseeingtriptoParis． ◆OpeningTimes HighseasonIApril～31OctobereverydayexceptMondays900～1830．Lastadmission1800． LowseasonNovember～31MarcheverydayexceptMondays900～1730．Lastadmission1700． ◆EntrytothePalace TogettothePalaceofVersaillesbyRERCrailline大区快铁C线makesuretobuyaParis﹣VersaillesRiverGaucheticketzones1～4． WithaParispassyoucanvisitthepalacefreeofcharge﹣that'sasavingofEuros．PleasenotethatVersaillesisoutsidezone3butsingleRERtraintickettoVersaillescostyouonly﹩3.25． WithaParispassyoudon'tneedtoqueueupbutcanuseprivilegedPassholderentryagreatbenefitifyouarevisitingduringthebusyspringorsummerseasons． ◆NoteYourentrydoesnotincludethemusicalfountainshows．Whenthewatershowsaretakingplaceyouwillbeunabletovisitthegardensunlessyoupurchaseaseparateticket． 1WhatcanwelearnaboutthePalaceofVersailles A．Itwasusedasamuseumatfirst． B．ItwasbuiltinmemoryofLouisXIV． C．Itwastheofficialseatofpowerin1830． D．ItisnotsobusyinNovemberasinOctober． 2IfavisitorwantstoenjoythePalaceofVersailleshewill． A．reachzone3ontime B．beallowedtovisititonMondays C．spendsomemoneytakingtheRERtrain D．alsowaitinthequeuelikeothertravelers 3Inordertowatchthewatershowsyouhavetobuy A．aParisPass B．aticketspeciallyforit C．asingleRERtrainticket D．aParisVersaillesRiverGaucheticket
已知向量若则＝．
Dujiangyanistheoldestman﹣madewatersystemintheworldand1wonderinthedevelopmentofChinesescience．Builtover2200yearsagoin2isnowSichuanProvinceinSouthwestChinathis3amazewatersystemisstilluesedtoday． InancienttimestheregioninwhichDujiangyannowstands4sufferfromregularfloodscausedbytheoverflowforthewaterfromtheMinjiangRiver．5helpthevictimsofthefloodingLiBingtheregiongovernortogetherwithhissondecidedtofinda6solve．LidesignedaseriesofchannelsbuiltatdifferentlevelsalongMountYuleithatwouldtakeawaythefloodwaterwhileleavingtheriverflowingnaturally．7goodstilltheextrawatercouldbedirectedtothedryChengduPlainmakingitsuitableforfarming． Oncethesystemwasfinishednomorefloodsoccurredandthepeoplewereabletolivepeacefully．TodayDujiangyanisadmiredbyscientistsfromaroundtheworldbecauseofonefeature．Unlikemoderndams8thewaterisblockedbyahugewallDujiangyanstillletswaterflowthroughtheMinjiangRivernaturally9enabletheecosystemsandfishpopulationstoexist10harmony．
在三棱锥P﹣ABC中PA⊥平面ABC∠BAC＝120°AP＝M是线段BC上一动点线段PM长度最小值为则三棱锥P﹣ABC的外接球的表面积是
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如图在四棱锥P﹣ABCD中底面ABCD为直角梯形AB∥CDAB⊥AD△PAB与△PAD均为等边三角形点E为CD的中点． 1证明平面PAE⊥平面ABCD 2若点F在线段PC上且CF＝2PF求三棱锥F﹣BEC的体积．
已知函数． 1求函数fx的单调区间 2是否存在实数a使得函数fx的极值大于0若存在求a的取值范围若不存在说明理由．
在△ABC中角ABC所对的边分别为abc且． 1证明acb成等比数列 2若c＝3且sin2C＝2cos2C+1求△ABC的周长
WhenIwasfiveyearsoldmymothersufferedfromdepression﹣andotherhealthissuesleavingmetocareforher．This1reversedourrolesaschildandcaretaker． WhileIknewmymotherwassickI2thateverythingwouldbeokay．3in1997everythingwenthorribly4andmylifechangedforever． Adoptionisan5wordtoafive﹣year﹣oldbutwhenI6thatmymotherhadsignedmeovertostrangersIfeltitwastheultimatebetrayal．Isufferedfromshock7andconfusionasIattemptedto8mynewfamily．IdidlearntolovemynewparentsthoughIcouldn'tforgivemymotherfor9me．Hearingpeopletellmethatshediditinmybestinterest﹣thatsheactually10me﹣mademebitter．Iinsistedthat11shehadtrullylovedmsshewouldhavemadeitworkforourlittlefamily． HowevertheolderIgotthemoreIbegantounderstandhow12oursituationhadbeen．Wehadbeen13boxesofnoodlesandweevenlivedinourcar．Ihavestartedtounderstandthe14sheputmeupforadoptionandthatshereallydidsaveme． OnlyrecentlyhaveIbegunto15howamothercouldgiveherchildtostrangersandIrealizenowwhatasacrificeitmusthavebeenforhertoletmego．Shewas16buteveninherstatesheunderstoodthatshewaspullingmedownwithher．Shelovedme17anythingsoshewantedmetohaveachanceinlifeonesherealisedshecouldnolonger18me．WhenIlookbacknowIam19toher．EventhoughIresented怨恨herforalongtimeInowknowmylifehasbeenaspecilagiftonlybecauseshewas20enoughtogivemeup． 1A．trend B．direction C．situation D．operation 2Arecognized B．believed Cadmitted D．explained 3A．However B．Therefore C．Otherwise D．Besides 4A．well B．wrong C．mad D．common 5A．exact B．right C．warm D．foreign 6A．regretted B．wondered C．realized D．expected 7A．cold B．hunger C．tiredness D．anger 8A．giveup B．worryabout C．adjustto D．searchfor 9A．rejecting B．raising C．criticizing D．accompanying 10A．blamed B．loved Cfeared D．forgot 11A．although B．if C．since D．unless 12A．familiar B．simple C．desperate D．stable 13A．throwingaway B．chargingfor C．dreamingof D．survivingon 14A．reasons B．risks C．rules D．results 15A．remember B．understand C．ignore D．describe 16A．upset B．sick C．polite D．calm 17A．otherthan B．ratherthan C．morethan D．lessthan 18A．lend B．control C．teach D．offer 19A．grateful B．similar C．equal D．rude 20A．curious B．patient C．selfless D．careful
已知函数fx＝|x﹣3|． 1若ft+f2t＜9求t的取值范围 2若存在x∈[24]使得f2x+|x+a|≤3成立求a的取值范围．
ThereisarestaurantinmyMainetownthathasdonelittletoupdateitselfoverthepast80years．Thisispartofitscharmasisthewoodenphonebooththatsitsneglectedintheageofthecellphone．Ahthephonebooth．Weneeditnowmorethanever． Formeitsymbolizesthatphonecallswereonceprivateaffairseveniftheinformationbeingsharedwasnotsensitiveinanyway．Itwassimplyassumedthataphonecenversationwasmeantfortwopeopleandtwopeopleonly． Growingupinthe1960swehadonlyphoneinthehouse．AsakidIdidn'tgetormakemanycallsbecauseallmyfriendsfivewithinearshotandIcouldjustyelloutthewindowifIwantedtheirattention．IdohoweverrememberansweringthephoneaskingfortheidentityofthecallerandthenhandingthephonetomymomShe'dtakeitsayHelloMrs…onemomentpleaseandthenassheplacedherhandoverthereceiversheturnedtomeanddirectedThisisforme．Whydon'tyougooutsideandplay Flashforwardtowhatcellphoneshavedonetoourlife．Withinthespaceofafewyearsoverhearingprivateconversationsseemstobenormal．NotlongagoIwassittinginBoston'sSouthStationnearamanwhowasonhiscellphonewaitingformytrain． ThefollowingiswhatthemanhadtosayYesthat'sright．Theredandyellowroses．Thenhecontinuedtorecitehiscardnumberaridexpirationdate有效期．Istaredatthefellow．HeglancedatmeandaskedWhatMyresponsewasimmediateIrecitedhiscardnumberbacktohimalongwiththeexpirationdate． Thereisnolongerasenseofpersonalbordersorlimits．Thecellphonehasbecomeamegaphone扩音器andIhavebeenprivy私下知情todetailsofpeople'slivesthatIwouldrathernotknow．Maybephoneboothscouldserveascellphoneharborstoday． 1WhatfeaturedoestherestaurantinMainetownhave A．Itisverypopular B．Itisold﹣fashioned C．Itwillclosedown D．Ithasbeenneglected 2Asakidtheauthor A．hadafewfriends B．oftencalledhisfriends C．wasnotallowedtoanswerthephone D．learnedthatphoneconversationsareprivate 3Whatistheauthor'sattitudetowardscellphone A．Critical B．Tolerate C．Optimistic D．Approving 4WhatdidtheauthordoinBoston'sSouthStation A．Hetalkedtoanoldfriend． B．Heboughtsomecolorfulroses． C．Heoverheardaman'spersonalinformation． D．Hehelpedastrangerwhowasmakingacall．
Theaye﹣ayeinthesamefamilyaspeoplemonkeysandapesisabout40cmlongwithabushytaleaboutthesamelengthasthebody．Thedarkbrownfurislongandwoollygivingtheanimalarathershaggy蓬松的appearance．TheyarefoundonlyonMadagascaranislandoffthecoastofAfrica．ItlivesinthetropicalforestsintheeastandnorthofMadagascar． Theaye﹣ayeismostlyarboreal栖息在树上的butissometimesseenwalkingontheground．It'sactiveduringthenightlookingaroundinthetreesforfood．Theaye﹣ayeisactuallythelargestprimate灵长类动物activeduringthenight．Largeeyeshelptheaye﹣ayefinditswayaboutatnight．Duringthedaytheaye﹣ayesleepsinanestinatree．Aye﹣ayesspendalmostthewholenighttravellingaboutandfeeding． Aye﹣ayeslivealone．Sometimespairsareseenbutbasicallylittleisknownabouttheirlives．Theydon'tleapandclingtotreeslikeotherprimates．Theymoveaboutonallfourlegs．Theyoccasionallymakebriefcriesbutareusuallysilent．Wormsinsidedeadwoodformthelargestpartoftheaye﹣ayediet．Theaye﹣ayealsofeedsonfruiteggsandbambooshoots． Thefrontfeetoftheaye﹣ayeareunique．Allthetoesarelongandthinbutthethirdisexceptionallylong．Theaye﹣ayetapsonthetreetrunkandlistensformovementasitsearchesforplaceswherewormsmightbelocated．Itbitesatthetreetomakehomesthenitusesitslongthirdfingertoreachinsideandhookoutworms．Thefrontteethoftheaye﹣ayegrowcontinuouslyandareworndownbyitseatingatbarkinitssearchforworms． Aye﹣ayesareclosetobegoneortotallygone．Becauseofdeforestation伐木orforestdestructiontheanimalshavethereforebeenforcedtoeatvillagers'cropsandmanyaye﹣ayeshavebeenkilledwhiledoingso．InadditionsomepeopleonMadagascarwillbelievethatseeinganaye﹣ayeisasignthatsomeoneclosetothemwilldiesotheykilltheanimalsonsight． 1Accordingtothefirstparagraphtheaye﹣aye． A．lookscolorful． B．hasahairlesstail． C．likesthehotplaces． D．soundslikemonkeys． 2Theaye﹣aye'sthirdfingerismainlyto． A．makeholesbigenough B．reachintotheholeforfood C．helpwalkfastontheground D．gettheanimalstofixonthetree 3Whatarereducingthenumberofaye﹣ayes A．People'sactivities． B．Environmentchanges． C．Globalwarming． D．Environmentalprotection． 4Whatisthepurposeofthepassage A．Toprotecttheaye﹣ayes． B．Tostopforestsbeingdestroyed． C．Tomaketheaye﹣ayeslivebetter． D．Tointroducetheaye﹣ayes．
已知函数fx＝xlnx﹣axa∈R． 1求函数fx的单调区间 2若fx+a≥0恒成立求a的值．
Indonesiaishometofouroftheworld'sworstpollutedriversandrankssecondwhenitcomestoplasticwaste．Sincesingle﹣usepackagingisalargecontributortotheproblemEvowareanIndonesian﹣basedcompanydecidedtohandlethatissuefirst．Andnowakindofedible可食用的packetshasbeeninvented． Afterinvestigatingvariousmaterialoptionsthecompanysettledonseaweed．Unlikecomcommonlyusedforcontainersseaweeddoesnotrequireresourceslikewaterorlargeamountsofspace．AccordingtoEvowareasmuchas40tonsofseaweedcanbegrowninanareathesizeofabaseballfield．Italsohelpsabsorbharmfulgreenhousegaseslikecarbondioxide．SinceIndonesianfarmersalreadyharvestmoreseaweedthantheycansellitiseasyforthecompanytofindthematerial． ThoughtheywillnotmakepublictheirproductionprocessEvowareannouncestheseaweedpackagingcontainsnochemicalsandissafetoconsume．Inadditiontowrappingfastfooditemsitcanalsobeusedtohousethingslikeinstantnoodleseasoning调味品andinstantcoffee． Thoughtheediblewrappersmaynothaveanytastethesamecannotbesaidaboutthesingle﹣usecupsthatthecompanyhasalsoinvented．Thesingle﹣usecupsthatcanbeusedtoservecolddrinksareavailablewiththetasteoforangeandgreentea． Whilereplacingplasticwiththeseaweedproductsmayseemlikeano﹣brainertomostofusitisahard﹣sellinIndonesia．AccordingtoChristianTheawarenessunderstandingandsenseofurgencytominimizetheuseofsingle﹣useplasticarestillverylow．Alsoafactoristhecostwhichishigherthanusingplastic． HopefullyEvowarewillsucceedinconvincingIndonesiansandpeopleworldwidethatswitchingtotheirproductswillgoalongwayinprotectingourbeautifulplanet． 1WhatisEvoware'spurposeofinventingeatablepackages A．Tomakefulluseofseaweed． B．Tomakegenerousprofits． C．Toattractmorecustomers． D．Toreduceplasticpollution． 2Whatcanwelearnaboutseaweedfromparagraph2 A．Itiseasytoget． B．Itbreaksdowneasily． C．Itishardtoharvest． D．Itcangrowinabaseballfield． 3Howaresingle﹣usecupsdifferentfromseaweedpackaging A．Theyarebeautiful． B．Theyhavedifferenttastes． C．Theyareinvariousshapes． D．Theyareenvironmentallyfriendly． 4Whatstopstheseaweedproductsbeingwidelyused A．Thehighcost． B．Theterribletaste． C．Thelackofseaweed． D．Thecomplexproductionprocess．
TheearthhaschangedoverandoveragainthroughoutthecourseofitshistoryInordertosurviveinchangingenvironmentsspeciesmustoftengothroughaprocessofadaptation．Adaptationreferstogeneticchangethatenablesanorganism生物体suchasananimalorplanttosurviveinitsenvironment．Iftheorganismsofaspeciescannotchangealongwiththeareainwhichtheylivetheyriskdyingout．Recenthistoryhasgivenusanimportantexampleofhoworganismsareabletosurviveoncetheirenvironmentschange． Lightgraypepperedmoths胡椒蛾anddark﹣coloredpepperedmothslivedinthecountrysidebetweenthecitiesofManchesterandLondoninEnglandManyyearsbeforethe19thcenturymoreofthelightgraypepperedmothshadbeenabletosurviveintheirenvironmentmostlybecauseoftheircolor．Birdscouldn'tseethelight﹣coloredmothsonthetreesbecausethecolorofthemothswassimilartothecolorofthetrees． Intheearly19thcenturythoughEnglandbeganthefirstyearsofitsIndustrialRevolution．Manyareasbecameoccupiedbyagrowingnumberoffactories．Manyofthesefactoriesneededcoaltoprovideenergyfortheirmachines．Whencoalbumsitgivesoffalotofdark﹣coloredsmokes．Thetreesbegantoblackenbecauseofallthesmokeintheairfromthefactories．Thismadethelightgraypepperedmothsmuchmorevulnerable．Birdscouldseethemonthetreesmoredearlyandeasilyhuntthemdown． SometimeinthenexthundredyearsscientistsbegantonoticeahugechangeinthemothpopulationlivinginandbetweenthecitiesofManchesterandLondon．Mostofthepepperedmothswereofthedark﹣coloredkind!Whatcausedthischangewasthefactthatbirdshadeatenalotofthelightgraypepperedmothsbecausethemothscouldbeseenclearlyonthedarkenedtrees．Thedark﹣coloredpepperedmothsintheareasurvivedmuchmoreeasilyandmatedwithotherdark﹣coloredpepperedmothsuntilmostofthepopulationofpepperedmothsbecamedark﹣colored． 32．Ifaspeciescan'tadapttothechangingenvironmenttheyarelikelyto． A．bedrivenoutoftheirhabitat． B．becomeextinct C．movetoanotherenvironment D．gothroughgeneticchanges 33．Whatconclusioncanbedrawnfromthechangeintwokindsofmoths A．Therewerepreviouslynodark﹣coloredpepperedmoths． B．Thelight﹣coloredpepperedmothsmovedtoanewenvironment． C．Thecolorchangehadnothingtodowiththechangeintheirenvironment． D．Darkcoloringwasbetterforthepepperedmothssurvivalinthe19thcentury． 34．Whatdoestheunderlinedwordvulnerableprobablymean A．Quicktochange B．Opentoattack C．Easilydefended D．Inastrongposition 35．Whatdoestheauthormainlydescribeinthepassage A．HowtheIndustrialRevolutionimprovedthelivesofworkers． B．Howtheearthchangedthroughoutthecourseofitshistory． C．Howhumaninfluenceorganismsthroughartificialselection． D．Hownaturalselectionchangedthepopulationofpepperedmoths．
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