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如图，不计电阻的圆形光滑导电轨道，内部有垂直于轨道平面的匀强磁场，一个导体棒可以绕圆心匀速转动，另一端用电刷和轨道相连，用导线把导体棒的O点和轨道连接起来，中间接一电阻R．导体棒在磁场的右半圆周匀速...
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高三下学期物理《》真题及答案
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如图a所示一对平行光滑轨道放置在水平面上两轨道间距l=0.20m电阻R.＝1.0有一导体静止地放在轨
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
如图所示一对平行光滑轨道放置在水平面上两轨道间距电阻R.＝1Ω有一导体杆静止地放在轨道上与两轨道垂直
如图所示相距为L.的两条足够长的光滑平行金属导轨与水平面的夹角为θ上端接有阻值为R.的定值电阻匀强磁
如图甲所示一对平行光滑轨道放置在水平面上两轨道间距l＝0.20m电阻R＝1.0Ω有一导体杆静止地放
如图所示质量均为m的导体棒a和b静止在光滑导电轨道上在水平轨道区域有垂直于轨道平面的匀强磁场现让a从
如图所示倾斜角θ=30°的光滑倾斜导体轨道足够长与光滑水平导体轨道连接.轨道宽度均为L=1m电阻忽略
如图所示光滑金属直轨道MN和PQ固定在同一水平面内MNPQ平行且足够长两轨道间的宽度L=0.5m轨道
如图所示有两根足够长不计电阻相距L.的平行光滑金属导轨cdef与水平面成θ角固定放置底端接一阻值为R
如图11所示abcd为平行金属板两板左端与电阻不计的光滑平行金属轨道相连两板右端接有电阻R匀强磁场垂
重为G.=0.1N的金属棒ab放在光滑的平行金属导轨上如图所示轨道间距为L=0.5m所在平面与水平面
如图所示在与水平方向成θ=30°角的平面内放置两条平行光滑且足够长的金属轨道其电阻可忽略不计空间存在
如图两光滑的平行金属轨道与水平面成θ角两轨道间距为L.一金属棒垂直两轨道水平放置金属棒质量为m电阻为
如图所示光滑金属直轨道MN和PQ固定在同一水平面内MNPQ平行且足够长两轨道间的宽度L.＝0.50m
20分如图所示一对足够长的平行光滑导轨放置在水平面上两轨道间距l＝0.20m定值电阻阻值R=1.0Ω
如图甲所示一对平行光滑导轨放置在水平面上两导轨间距l＝0.2m电阻R.＝1.0Ω有一导体杆静止地放置
如图所示有两根足够长不计电阻相距L.的平行光滑金属导轨cdef与水平面成θ角固定放置底端接一阻值为R
如图所示光滑平行金属轨道的倾角为θ宽度为L.电阻为R..在此空间存在着垂直于轨道平面的匀强磁场磁感应
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如图所示两根相距L.平行放置的光滑导电轨道与水平面的夹角均为轨道间有电阻R.处于磁感应强度为B.方向
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为研究低温对某种热带植物叶绿体结构和代谢的影响科研人员选用长势一致的两个品种的幼苗分别在28℃和0℃条件下处理一段时间后测定幼苗叶片离体叶绿体的放氧量和叶绿体中MDA含量MDA是膜脂质分子过氧化产物其含量反映叶绿体膜的受损程度结果如图．请回答 1测定离体叶绿体放氧量实验中需要控制的无关变量有至少两项． 2离体叶绿体中放氧的场所是与氧气同时产生的物质将进入直接参与过程． 3根据实验结果分析叶绿体中MDA含量与膜受损程度呈填“正”或“负”相关．低温胁迫引起放氧量下降的原因是使叶绿体中色素含量． 4本研究表明两个品种中较耐低温的是．
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处错误每句中最多有两处每处仅涉及一个单词的增加删除或修改. 增加:在缺词处加一个漏字符号∧并在其下面写出该加的词. 删除:把多余的词用斜线\划掉. 修改:在错的词下面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. Idon'tknowwhattoexpressmysincereapologytoJimbecauseIlostthebookhelentittome.Iwasverygratefulwhenheputabookonmydesk.InordertogiveitbacktohersoonIspentthreedaysreadit.ThenextdayItookthebooktoJim'sclassroomtoreturnit.LuckilyIcouldn'tfinditanywherewhenIarrivedathisclassroom.TherewasobviousthatIcouldn'tgiveitbacktohimasIpromisedbefore.WhatshouldIdonow?Idecidetobuyanewonetohimandwritealetterofapologytohim.ThelessonformeisthatIshouldtakegoodcareofwhatbelongtome.
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利用科学记数法表示的数原来各是什么数1.732×10²=
科研人员利用图1所示固定化乳糖酶反应装置降解牛奶中的乳糖并研究了乳糖酶凝胶珠颗粒大小对降解效果的影响．实验时将3种不同大小的凝胶珠分别放在反应柱中打开活栓然后以相同的速度向每个反应柱中加入等量的牛奶测定收集的牛奶中葡萄糖的浓度结果如图2．请回答 1乳糖酶催化乳糖降解为葡萄糖和． 2制备固定化乳糖酶凝胶珠时溶解海藻酸钠宜采用的方法．应用溶液浸泡凝胶珠使其形成稳定结构． 3与固定化细胞相比固定化酶时使用的海藻酸钠浓度应适当这样可以减少． 4本实验结果表明直径为mm的乳糖酶凝胶珠降解乳糖的效果较好分析其原因是． 5在凝胶珠颗粒直径一定时控制牛奶流经反应柱的速度测定不同流速下收集的牛奶中葡萄糖浓度．请在相应位置的坐标中绘制收集的牛奶中葡萄糖浓度相对值与流速之间的关系曲线．
Whatcouldhomesofthefuturebelike?Nooneknowsexactly.Butpreparationsaremadefortheworld'sfirstfreeform3D﹣printedhouse. ExpertswillbuildahousecalledCurveAppealwhichwillbe3D﹣printedoff﹣sitebeforebeingputtogetheron﹣sitetocreatetwooutsidewallsaroofandaninsidepart.Thesefourmainpartswillthenbejoinedtogether. Although3D﹣printedbuildingshavebeenmadebeforethishome﹣﹣﹣tobebuiltinChattanoogaTennesseelaterthisyear﹣﹣﹣willbethefirstofitskindasitwillcontainnoregularshapesorangles.ThehouseisthecreationofthedesigncompanyWATGbasedinLondonandCalifornia.ThedesignforCurveAppealdrawsinspirationfromtheCaseStudyHouseprogram. Thearchitects建筑师leadingtheprogramwerefamousfortryingtocreateopen﹣planspacethataddsnaturallight.InawrittenstatementaspokesmanforWATGsaidUsingmanyofthesamemoderndesignprinciplesCurveAppealisthenextdevelopingstep.It'simportantthatthebuildingsandtheenvironmentworktogetherharmoniously.ThechosensiteforCurveAppealisstepsawayfromtheTennesseeRiverinabeautifulwoodedsunlitarea. WATGwasawardedthefirstprizeintheFreeformHouseDesignChallengein2016andgivenprizemoneyof﹩8000tomakeitsplansareality.Thecompetitionwasdesignedforarchitectsdesignersengineersandartists. Competitorswerechallengedtodesigna600to800﹣﹩qftsingle﹣familyhomethatrethinkstraditionalaesthetics美学constructionbuildingsystemsandstructure. OverthelastyearWATG'sChicagoofficehasbeendevelopingtheirdesignwithBranchTechnology.Thisprojectwillbecompletedlaterthisyear.OncecompletedtheCurveAppealhomewillhaveopenandlight﹣filledinsidelivingspace. 1WhatcanweknowaboutCurveAppealfromthepassage? A.Itwillbedifferentfromanordinaryhouse. B.Itisthefirst3D﹣printedbuilding. C.Ithasvisiblewallsbutnoroof. D.Itwaseverbuiltintheworld. 2Whereisthefreeform3D﹣printedhouselocatedaccordingtoParagraph4? A.FarawayfromtheTennesseeRiver. B.InthewoodsneartheTennesseeRiver. C.NearWATG'sChicagooffice. D.Nexttosomemodernbuildings. 3WhatdoestheFreeformHouseDesignChallengedo? A.Itinspirespeopletodesignwhattheylike. B.Itonlyacceptsdesignsintraditionalways. C.Itofferscompetitorsinspirationwhennecessary. D.Ithelpsputcreativeideasintopractice. 4What'sthepassagemainlyabout? A.Thedesignofhomesinfuture. B.TheFreeformHouseDesignChallenge. C.Theworld'sfirstfreeform3D﹣printedhouse. D.Thedevelopmentof3D'sprintinginarchitecture.
Backabout10monthsagoIstartedcollegeandjuststruggledwitheverythingsuchasclassesandfriends.Iquicklybecamedepressed抑郁的andangryatmyselffornotbeingabletodobetterinschoolinadditiontolack缺少offriendsduetopoorsocialandcommunicationskills. Thiswentonformonthsuntilmy19thbirthday.Myparentssentmeagreatcake.ButIabsolutelyhadnoonetoshareit.Ithrewoutthecakeafterhavingonepiecewithabout90%ofitleftover.ThatnightIwasdepressedsoIdecidedtogooutsidetothefreezingtemperatureofthewinterandrun.Iputmyearphonesinandranabout2milesat11p.m.onmybirthday. WhenIgotbackinsideIwasproudofwhatIwasabletodo.ThenextnightIdidthesame.Iwasn'tquickorfitbutIwentoutsideanddidsomething.Therunningcontinuedfor2monthsuntilIfinallyhadcouragetogotothegymwhereIstartedswimmingasIusedtodoinhighschool.AmonthwentbyandIstartedliftingweightandcontinuallyrunning. LookingbackIcanseethatexercisehelpedcure治愈mydepressionbutitdidn'tonlydothat.AtthegymImetnewfriendsandbackatmydormIgrewconfidenttoplaySuperSmashBrotherswithmyclassmates. NowIexerciseforonehourandahalfeverydayandlookforwardtothat.IgetdailytodowhatIlovewithpeoplewholoveitaswell.Ihopethishelpssomeonewhomaybeorhavebeeninasimilarsituation. 1Whatmadetheauthordecidetorunatnight? A.His19thbirthday. B.Hisparents'cake C.Hisloneliness. D.Hisroommates. 2Whichofthefollowingbestdescribestheauthor? A.Determined. B.Humorous. C.Generous. D.Selfless. 3Whatisthebiggestbenefitoftheauthor'srunning? A.Losinghisweight. B.Regaininghisconfidence. C.Playingwithhisparents. D.Joiningotheractivities. 4Whydoyouthinktheauthorwrotethispassage? A.Tointroducehislifeincollege. B.Toshowhisthankstohisparents. C.Toemphasizetheimportanceoffriendship. D.Tosharehisexperienceofdealingwithhardship.
江苏某城市为有效降低污水中的有机物和氮磷含量建立了如图所示的污水综合处理系统厌氧池和阶梯跌水曝气塔的池体填料中含有大量的活性微生物．请回答 1污水排放会引起水体富营养化藻类等浮游生物大量繁殖加之死亡后被微生物分解引起水体的溶解氧下降造成鱼类等死亡进一步破坏了生态系统稳态这种调节机制称为． 2厌氧池中的微生物在生态系统中属于．厌氧池中的微生物降解有机物的能力强原因是． 3设计阶梯跌水曝气塔的优点是污水流经阶梯跌水曝气塔时将其中的NH转化成NO和NO的生物是． 4在相应位置的图解中用箭头补全人工湿地中碳元素的转移途径．
BooksforKids ●LesserSpottedAnimalsbyMartinBrown ImageSource:Scholastic Haveyoueverheardofanumbat食蚁兽ordzorilla非洲艾鼬?Noneitherhadwe.Thankstothisunusualpicturebookbothyouandyourlittleanimalloverscanlearnaboutawholegroupofnewcreatures.Beware:Youmaystartaskingforforeignpetsafterturningthesepages. AvailablefromAmazon＄14.47 ●HowtoAvoidExtinctionbyPaulPaulAcampora ImageSource:Scholastic YourmiddleschoolerwillcertainlyenjoyjumpingintoanoldBuickalongwithLeohis16﹣year﹣oldcousinandalovelydognamedKermitonacross﹣countryroadtrip.Thisfuncomedicbookfilledwithfoodfamilyandfossilswillteachkidsaboutlifeinawaytheycangrasp.Ifyou'relookingforagoodreadforyourkidsthisisit. AvailablefromAmazon＄8.95 ●What'sOutThere?byLynnWilson ImageSource:PenguinRandomHouse DoyouhaveaCuriousAstronaut﹣wannabeonyourhands?ThisclassicReadingRailroadbookwillteachyourchildwhatthesunismadeofwhatcausesthemoontochangeshapeandallabouttheplanetsinjustafewpages.Thisbookissimplyoutofthisworld. AvailablefromAmazon＄3.99 ●ScienceStunts:Fun.FeatsofPhysicsbyJordanD.Brown ImageSource:PenguinRandomHouse Doesyourlittlescientistalsolovemagic?We'vefoundtheperfectbookforthem!They'llbeshockedbythewaythesesimplemagictrickscancometogetherwiththehelpofabitofscience.Thisisonebookthatwillhaveyousmilingfromeartoear. AvailablefromAmazon＄12.59 1Peterwhoisananimalfanmaylikeread. A.LesserSpottedAnimals B.HowtoAvoidExtinction C.What'sOutThere? D.ScienceStunts:Fun.FeatsofPhysics 2WhatcanchildrenlearnfromthebookWhat'sOutThere? A.Funofscience. B.Extinctionofspecies. C.Knowledgeoftheuniverse. D.Experienceofaforeigntour. 3Whichbookmaymakechildrenburstintolaughter? A.What'sOutThere? B.LesserSpottedAnimals C.HowtoAvoidExtinction D.ScienceStunts:Fun.FeatsofPhysics
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Myfirstlessonwasatameeting.AswesettledaroundthetableIheardMegwhowas1arecentoperationtalkingtoJudiththemanagerofourprojectThankyousomuchfor2mydaughterstotheirdancelessonlastweek.Don'tmentionitJudithsaidItwasnothing. Knowinghow3JudithwaswithherworkkidsandagingparentsIfoundherdrivingMeg'schildrentodancelessonsunbelievably4. IwasabouttosaymoreaboutthiswhenDonnaanothercolleagueenteredtheroom5. Sheapologizedforbeinglatesayingshejusthadhostedalunchforherfriendswhowereoverseventy.ThatwassoniceofyouIsaid6howshedidn'tliketocookorclean.Ohshesaidwavingher7Itwasnothing.SomehowIcouldstilltellthe8inhervoice.Shegainedasenseofsatisfactionfromtheentertainment款待offeredtoherfriends. Seeingtheir9tohelpothersselflesslyIstartedthinkingabouttheconceptofnothingthispeacefulandgenerouswayofliving﹣﹣﹣wasitreallynothingorweretheysimplysayingthat?Isuddenly10thatonceIspentawholeafternoonafterworkhelpingafriend11aspeechshewasgoingtodeliver.I12hertorearrange重新安排theorderofthestoriesinthelecturetomakeitsoundmore13.Afterthefifthtryshefinally14it.Shehuggedmewith15sayingthankstome.Ismiledandsaiditwasnothing. SuddenlyIrealizedthathelpingsomeonewasreallysomethingtome.Ilearntthatgivingfromtheheartdoesn't16meanhardwork.The17isfindingsomethingwelovetodoandfindingsomeonewho18thatsomething.Ourgenerositycan19othersaswellasourselves.Onceyouhaveagood20ofitit'snothing.Andit'sreallysomething. 1A.recoveringfrom B.adaptingto C.goingthrough D.joiningin 2A.guiding B.fetching C.driving D.dragging 3A.common B.busy C.strange D.practical 4A.frightened B.sincere C.gifted D.generous 5A.hurriedly B.disappointedly C.angrily D.unexpectedly 6A.ignoring B.knowing C.forgetting D.predicting 7A.eyes B.feet C.leg D.hand 8A.pleasure B.sadness C.surprise D.regret 9A.progress B.adventure C.promise D.willingness 10A.referred B.refused C.remembered D.respected 11A.preparefor B.putup C.giveaway D.takeapart 12A.begged B.invited C.advised D.permitted 13A.unbelievable B.reasonable C.sensitive D.puzzling 14A.got B.meant C.caught D.made 15A.concern B.worry C.gratitude D.apology 16A.normally B.accidentally C.necessarily D.possibly 17A.treat B.trick C.belief D.plan 18A.needs B.admires C.loves D.defends 19A.defeat B.benefit C.win D.regard 20A.order B.balance C.impression D.command
杜氏肌营养不良症一般在3～5岁时开始发病20～30岁因呼吸衰竭而死亡受一对等位基因Dd控制．亨廷顿舞蹈症一般在中年发病受另一对等位基因Hh控制．如图是某家族两种遗传病系谱图其中Ⅰ3不携带致病基因．请回答 1利用DNA分子杂交技术鉴定Ⅰ3是否携带致病基因的原理是． 2该家族中杜氏肌营养不良症和亨廷顿舞蹈症的遗传方式分别是． 3Ⅰ4的基因型是．Ⅱ3产生同时含有两种致病基因卵细胞的概率是． 4Ⅲ3患杜氏肌营养不良症的概率是． 5若Ⅲ2与一正常男性婚配生一男孩该男孩正常的概率是．
利用科学记数法表示的数原来各是什么数-5.002×104＝
Fishingisapopularactivityandeveryfishermanknowstherule:Keepthebigonesthrowthesmalleronesback.Theideabehinditissimple﹣thelargerfishareprobablyolder.Ifyoukeepthesmalleronestheywon'tbeabletoreproduceandthefishpopulationwillbeindanger. Butfishingoutthelargestfishfromapopulationhasanunwantedeffect:Overtimefeweradultfishgetreallybig.Ifonlythesmallerfishreproducethenfuturegenerationswillbecomesmaller.Thisisanexampleofevolution进化inaction. OnescientistDr.DavidConoverhasspentthelastdecadestudyingtheeffectsofthekeepthebigonesruleandiftheycanbechanged. TosetuphisexperimentConoverandhisteamcaughthundredsofsilversidefishanddividedthemintosixgroups.FortwogroupsConoverfollowedtheukeepthelargeonesruleandtookoutthebiggestfish.Fortwoothergroupsheremovedonlythesmallfish.Forthelasttwogroupsheremovedfishatrandom随意的. Afterfiveyearshemeasuredthefishineachgroup.Inthetwogroupswherethelargestfishwereregularlyremovedtheaveragefishsizewassmallerthantheaveragesizeintheothergroups.Herewastheevolutioninaction:Ifonlysmallfishsurvivetoreproducethenfuturegenerationsoffishwillalsotendtobesmall. ForthesecondfiveyearsofhisexperimentConoverchangedtherulesandtookfishrandomlyfromeachgroup.Attheendoftheexperimenthefoundthatthefishthatwereinthekeepthelargeonesgroupforthefirstfiveyearshadstartedtogetlargeragainalthoughhecalculateditwouldtakeatleast12yearsforthefishinthatgrouptoreturntotheiroriginalsize. Inotherwordsittakeslesstimetoshrinkthanitdoestorecover. 1What'sthetraditionalruleinfishing? A.Keepbothbigandsmallones. B.Keepbigonesandfreesmallones. C.Keepsmallonesandthrowbigonesback. D.Keeptheonesthatcanreproduce. 2DavidConoverdidexperimentonfishinginorderto. A.findpracticalrulesinfishing B.provethetraditionalfishingrulewasreasonable C.seekforgoodfishestoreproduce D.findgoodmethodinraisingsilversidefish 3WhatdidDavidConoversexperimentprove? A.Fishermanshouldfishatcertaintime. B.Fishermanshouldkeepbigonesandfreesmallone. C.Fishermanshouldkeepsmallonesandthrowbigonesback. D.Fishermanshouldkeepfishatrandom. 4Whatdoestheunderlinedwordshrinkmeaninthelastparagraph? A.Becomesmaller. B.Becomeill. C.Becomeweaker. D.Becomeless.
ThefirstMondayinSeptemberisLaborDayintheUnitedStates.Thenationalholidaybeganmorethan100yearsago1honorlow﹣paidfactoryworkers. LaborDayalso2informalmarkstheendofsummer.ManystudentsreturntoschoolafterLaborDay.Thehotdaysofsummerturn3cool.ManyAmericanscelebratetheholiday4anoutdoorfamilybarbecue. ButLaborDaystartedwithastruggle.OnMay1st1889workersdemonstrated游行onthestreetsofParisFrance.InternationalLaborDaywasborn.Mostindustrialized5countryintheworld﹣excepttheUnited StatesandCanada﹣﹣celebrateLaborDayonthefirstofMay. ThefirstAmericanLaborDaycelebration6holdonSeptember5th1882inNewYorkCity.About10000workersmarchedthroughthestreetstoshowthe7strongoflabororganizations. FormanyyearsafterthatAmericanworkersusedthefirstMondayinSeptembertodemandbetterworkingconditionsandpay.Musicwasapartofmanyofthosemarchesandmanylaborsongstraditionallytellstoriesofconflictandhopesfor8betterlife.HereareWeShallNotBeMoved.WhichSideAreYouOn?BreadandRoses. EventhoughLaborDaydemonstrationsarenot9commonastheyareintheU.S.thesongremindsustocelebratetheeffortandlovethatmanypeoplegiveto10theywork.
下列关于人体内性激素的叙述正确的是
Youmayfinditexcitingtogetapart﹣timejobduringthesummervacation.1Whenyougetaninvitationtoajobinterviewyouarehalfwaytowardsyourgoal﹣﹣ajoboffer.Hereareafewthingsyoushoulddoafterwards. Respondtotheinvitationtotheinterview.Thankthesenderfortheirtimeandfortheopportunitytoorganizetheinterviewconfirmingthatyouwillbeavailableatthedeterminedtime.2. 3Youneedtodosomeresearchonthecompanyandlearnasmuchaboutthecompanyaspossiblebeforetheinterview.Usethecompany'swebsiteandnewspaperarticlestogatherasmuchinformationaspossible.Youshouldalsobereadytotalkindepthaboutthecompanyandthepositionyouareapplyingfor. 4It'sbesttoprepareforawidevarietyofquestionsbythinkingaboutyourowncareergoalsandsoon.Wheredoyouseeyourselfinfiveyears?isacommonquestion.Workingdiligentlyforyouofcourse!Butunlessyouareactuallytryingtogetajobinyourchosencareerthisprobablyisn'tagoodanswer. Practicewithafriend.5Notonlywillthisgiveyouawaytostructureyourpreparationbutitwillalsohelpyougetcomfortablewithgivinganswers.Practicegivingconcisecompleteanswersandmaintainingeyecontactwiththeinterviewerswhileyougivethem. A.Askpeoplearoundyouforhelp. B.Ifyouhaveafriendwhoisalsopreparingforaninterviewconsiderpreparingtogether. C.Ifyouneedmoreinformationabouttheinterviewthisisthetimetoask. D.Butdoyouknowhowtoprepareforajobinterview? E.Thinkaboutquestionstheinterviewerislikelytoask. F.Whatarethechancesforprofessionalgrowthinthisjobopportunity. G.Doyourhomework.
下列关于细胞生命历程的叙述正确的是
利用科学记数法表示的数原来各是什么数2×105=
科学家构建了含有大洋鳕鱼抗冻蛋白基因启动子和大鳞鲑鱼生长激素基因的表达载体并将其导入了大西洋鲑的细胞中获得了生长速度加快的转基因大西洋鲑．相关叙述正确的是
把下列数据用科学记数法表法出来地球上煤的储量估计为15万亿吨以上．
假定你是李华你在某贴吧上看到美国孔子学院ConfuciusInstitute的学生Henry发帖希望通过网络视频互动学习中国诗词.请你给他写封邮件内容包括: 1.表示愿意帮助他; 2.说明你想帮助他的原因. 注意: 1.词数100左右; 2.可以适当增加细节以使行文连贯.
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