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某研究小组拟合成医药中间体X和Y． 已知：①；②；③ 请回答：（1）下列说法正确的是 ． A．化合物A不能使酸性KMnO4溶液褪色 B．化合物C能发生加成、取代、消去反应 C．化合物D...
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高三下学期化学《》真题及答案
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对乙酰氨基酚合成的关键中间体是其结构式为
氢化可的松半合成过程的主要中间体有或等
【化学——选修有机化学基础】15分某研究小组以甲苯为主要原料采用以下路线合成医药中间体F.和Y.已知
某研究小组以甲苯为主要原料采用以下路线合成医药中间体F.和Y.已知请回答下列问题1下列有关F.的说法
氯乙烯合成岗位中间体质量指标
依曲替酯是一种皮肤病用药它可以由原料X.经过多步反应合成下列说法正确的是
原料X.不能使酸性KMnO
4
溶液褪色
原料X.酸性条件下的水解产物与中间体Y.互为同分异构体
中间体Y.能发生加成、取代、氧化等反应
1 mol依曲替酯只能与1 mol NaOH发生反应
某药物的中间体F和某塑料G的合成路线如下 A中所含官能团的名称为G的结构简式
依曲替酯是一种皮肤病用药它可以由原料X.经过多步反应合成下列说法不正确的是
原料X.与中间体Y.互为同分异构体
原料X.可以使酸性KMnO
4
溶液褪色
中间体Y.能发生加成、取代、消去、氧化、还原反应
1 mol依曲替酯能与2 mol NaOH发生反应
依曲替酯是一种皮肤病用药它可以由原料X.经过多步反应合成下列说法不正确的是
原料X.与中间体Y.互为同分异构体
原料X.可以使酸性KMnO
4
溶液褪色
中间体Y.能发生加成、取代、消去、氧化、还原反应
1 mol依曲替酯能与2 mol NaOH发生反应
tRNA分子合成不是中间体mRNA的需要
2013年1月13日中国应用技术网报道了利用苯制备偶氮染料和医药中间体的方法下面是制备偶氮染料F和医
化合物X.是一种有机合成中间体某研究小组采用如下路线合成X.和一种常见的高分子化合物D.首先合成D.
化合物X是一种有机合成中间体Z是常见的分子化合物某研究小组采用如下路线合成X和Z 已知①化合物A
【化学—选修5有机化学技术】15分2013年1月13日中国应用技术网报道了利用苯制备偶氮染料和医药中
2013年1月13日中国应用技术网报道了利用苯制备偶氮染料和医药中间体的方法下面是制备偶氮染料F.和
石油化工产品是工业的重要基本原料和中间体
炼油
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某研究小组以甲苯为主要原料采用以下路线合成医药中间体F.和Y.已知请回答下列问题1下列有关F.的说法
某研究小组以甲苯为主要原料采用以下路线合成医药中间体F.和Y.已知①②请回答下列问题⑴下列有关F.的
某药物中间体的合成路线如下下列说法正确的是中间体
对苯二酚在空气中能稳定存在
1 mol该中间体最多可与11 mol H
2
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该中间体分子中含有1个手性碳原子
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中间体Y.能发生加成、取代、氧化、还原反应
原料X.可以使酸性KMnO
4
溶液褪色
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Wespendsomuchtimewaitingtobelovedhopinglovewillfindusandlookingforthatspeciallove.Unfortunatelythat'snotusuallyhowlifeworks.Tobelovedyoushouldloveandrespectyourselfasmuchasyoudoothers.Inordertolovesomeoneyoushouldloveyourself. ●Stopcomparingyourselftoothers.1.Weallhavedifferentgifts.Whenyoucompareyourselftoothersforwhattheyhavewhetheritisacarahouseorajobitmakesyoufeelbadaboutyourself.Reallybegratefulabouteverythingyouhave.Gratitudekeepsyourheartopentolove. ●Practicereceivinglove.Totrulyloveistobeabletoreceiveit.Whensomeonelovesyoudoessomekinddeedstoyouorsayskindwordsacceptit.2.Knowthatyouareworthyoflove.Itisimportanttoacceptagiftoflovebyothers.Yougiveyourselfachancetolearnmoreaboutyourselfthatyouarelovable.3. ●4.Writeaboutyourexperiencesgoodandbad.Whenyouwritedowngoodexperiencesallowyourselftofeelthosefeelings.Whenyourememberbadexperiencesallowyourselftofeelself﹣compassion.Compassionisnotself﹣pitybutratherwillingnesstoacceptone'sownpainandregret. ●Stoptryingtobeperfect.Stopblamingyourselfforbeinglessthanperfect.5.Justfollowallthestepsaboveanddon'tletanyone'sexpectationsofyouputanypressureonyou. A.Keepadiary. B.Appreciateyourself. C.Everyoneontheearthisunique. D.Dosomethinginreturnforhimorher. E.Yougivesomeoneajoyofgivingbylovingyou. F.Allowyourselftofeelthelovethathascomeyourway. G.AlwaysdoyourbestbutnotreachingperfectionisNOTfailure.
如图所示圆筒形导热气缸分上下两部分下面部分A的截面积是上面部分B的截面积的两倍A的高度为L．初始时活塞刚好在A与B交界处使A中封闭有一定量的理想气体B与大气相连距离气缸底部2L处有卡环能限制活塞移动．已知大气压强为P0活塞质量为M现把气缸倒置过来．求稳定后A中气体的压强是多大重力加速度为g不计活塞与气缸之间的摩擦
设函数fx＝ax2+blnx﹣x已知曲线y＝fx在点1f1处的切线与直线x﹣y+1＝0垂直． 1求a的值 2求函数fx的极值点．
如图所示为一玻璃砖的横截面其中OAB是半径为R的扇形∠AOB＝45°OBD为等腰直角三角形．一束光线从距O点R的P点垂直于OD边射人光线恰好在BD边上发生全反射最后由AB边射出．已知光在真空中的传播速度为c求 i玻璃砖对该光线的折射率 ii光在玻璃砖中传播的时间．
SallyDawlyisawomanfromAuburnCalifornia.Overthelastthreeandahalfyearstheanti﹣litteringwomanhasspentmostofherfreetimepickingupcigarettebutts烟头fromthestreetsofherhomecity. CalledtheButtLadybyherlocalcommunityDawlybeganhermissiontoridthestreetsofhercityofcigarettebuttsinOctober2014.Thewomanlookedforcigarettebuttspickedthemupandthrewtheminthetrash.TokeepacountofhowmanybuttsshepicksuptheButtLadyhasbeenusingatabletandearlierthismonthshehitahistoricmilestone﹣onemillioncigarettebutts. IgottiredofgoingonmywalksandseeingcigarettebuttseverywhereSallyDawlysaid.I'mjustshockedthatIhadtopickupsomany.I'veeverpickedup3000buttsinonedayshesaid.Don'tthrowawayyourbuttsbetteryetstopsmoking. Withsomanycigarettebuttslitteringthestreetscanoneperson'seffortsreallymakeadifference?Surprisinglytheanswerseemstobeyes.SoonaftertheButtLadyofAuburnstartedhermissionandwordofhereffortsspreadcigarettecansstartedappearingaroundbarsandrestaurantsinthecity.Membersofthelocalcommunityevencameouttocheerheronassheapproachedherone﹣million﹣buttmilestone. Sallyknowshercity'scigarettebuttlitteringproblemwon'tbesolvedanytimesoonbutshehopesherworkwillinspirepeopletoatleastthinktwicebeforedroppingcigarettebuttsinthestreets.Shehasdecidedtocontinuecleaningupafterirresponsiblesmokersandalreadyhasanewmilestoneinhersights﹣twomillioncigarettebutts. WordoftheButtLady'seffortstokeepthestreetscigarettebutt﹣freehasreachedneighboringcommunitiesaswellandCBSSacramentoreportsthatothercitieshavestartedseekingherhelpaswell. 1WhydoesSallyDawlycarryaniPadwithherwhilepickingupthebutts? A.Toentertainthecrowds. B.Tomonitorthesmokers. C.Toattractpeoplesattention. D.Torecordthenumberofbutts. 2HowdidSallyDawlyfeelwhenpickingupcigarettebutts? A.Excitedbutupset. B.Shockedandsorry C.Frightenedbutcontent. D.Astonishedanddesperate. 3Fromthetext.whatcanbeinferredaboutSallyDawly? A.Shepicksupnearly3000cigarettebuttseveryday. B.ShewillworkinothercitiesinCaliforniainthefuture. C.Shehassetanewgoalofpickinguptwomillioncigarettebutts. D.Shepickeduponemillioncigarettebuttswithmembersofhercommunity. 4Whatisthetextmainlyabout? A.California'sButtLady. B.Fightingagainstsmoking. C.Californianshealthproblems. D.SmokingproblemsinCalifornia.
如图直三棱柱ABC﹣A1B1C1中DE分别是ABBB1的中点． 1证明BC1∥平面A1CD 2设AA1＝AC＝CB＝2AB＝2求三菱锥C﹣A1DE的体积．
地面上方足够高处有一点P质量为0.5kg的带负电小球从P点由静止自由落下在2s末加上足够大竖直向下的匀强电场再经过2s小球又回到P点．不计空气阻力取g＝10m/s2则下列说法正确的是
在如图甲所示的电路中理想变压器原副线圈匝数比为21．ab两端电压与时间的关系如图乙所示二极管可视为理想二极管电表均为理想电表电阻R＝10Ω则下列说法正确的是
如图所示面积为S的矩形线圈共N匝线圈总电阻为R在磁感应强度为B方向垂直纸面向里的匀强磁场中绕竖直轴OO′以角速度ω匀速转动图示位置C与纸面共面位置A与位置C成45°角．线圈从位置A转过90°到达位置B的过程中A位置磁通量为正下列说法正确的是
如图所示足够长的光滑平行金属直导轨固定在水平面上左侧轨道间距为2d右侧轨道间距为d．轨道处于竖直向下的磁感应强度大小为B的匀强磁场中．质量为2m有效电阻为2R的金属棒静止在左侧轨道上质量为m有效电阻为R的金属棒b静止在右侧轨道上．现给金属棒a一水平向右的初速度v0经过一段时间两金属棒达到稳定状态．已知两金属棒运动过程中始终相互平行且与导轨良好接触导轨电阻忽略不计金属棒a始终在左侧轨道上运动则下列说法正确的是
如图所示实线表示某电场中的电场线但方向未知虚线是某一带负电的粒子通过该电场区域的运动轨迹AB是运动轨迹上的两点．若带电粒子在运动中只受电场力作用在AB两点的电势分别为φAφB加速度大小分别为aAaB速度大小分别为vAvB电势能大小分别为EpAEpB则下列说法正确的是
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我国将于2020年完成35颗卫星组网的北斗全球卫星导航定位系统．北斗是由5颗静止轨道卫星和30颗非静止轨道卫星构成的全球定位系统30颗非静止轨道卫星中有27颗是中轨道卫星中轨道卫星的轨道高度约为21500km静止轨道卫星的高度约为36000km知地球半径为6400km关于北斗导航卫星下列说法中正确的是
TheVanGoghMuseuminAmsterdamhaswelcomedhometwopaintingsbytheDutchmastermorethan14yearsaftertheywereripped抢offthemuseumswallinanighttimetheft.MuseumdirectorAxelRuegercalledtheirreturnoneofthemostspecialdaysinthehistoryofthemuseum. ThepaintingswerediscoveredlastyearbyItalianpolicewhiletheyweresearchingthesuspectedItaliancriminalsfarmhousenearNaplesforevidenceofdrugdealing.Thetwopaintingswerewrappedincottonsheets.Theywerestuffedinaboxandhiddenbehindawallinatoiletwhentheywerefound. Thepaintingswereconsideredamongtheartworksmostsearchedforintheworld.AfteryearsindarknesstheycannowshineagainTheyarebackondisplayatthemuseumbeforebeingtakentotheconservationstudioforrepairs.Fortunatelytheysufferedremarkablylittledamageasthieveswhohadclimbedupaladderandbrokenawindowtogetintothemuseumin2004rippedthemoutoftheirframes. Itisnotonlyasurprisethattheworkshavebeenrecoveredbutit'sevenmoresurprisingtheyareinrelativelyunharmedcondition.Ruegersaid. ThemuseumdirectorwasonvacationwhenthecallcamelastyearfromItalianauthoritieswhobelievedtheyhadrecoveredthepaintings.Hedidn'tcelebraterightaway.He'dhadcallslikethisbefore. Iwashopefulbutalsoalittlehesitant.Overtheseyearswehadsomanyoccasionswhenpeoplephoneduscontactedusclaimingthattheyknewsomethingaboutthewhereabouts下落oftheworksandeachtimeitwasfalsethetracewentcoldhesaid.So…thewayhasbeentillofdisappointment.ButmuseumexpertssenttoItalytochecktheauthenticity真实性oftheworksquicklyturnedRueger'sdoubtsintodelight. RuegersaidthepaintingsarenowbackpermanentlyatthemuseumwhichishometodozensofworksbyVanGogh.I'mveryconfidentthateverythingissafeinthemuseumfromnowonhesaid. 1Howwerethestolenpaintingsfound. A.Thepolicefoundthembyaccident B.Thearrestedthievesgaveinformation C.Somedrugdealersofferedclues D.Thepoliceknewthehiddenplace 2WhatsurprisedRuegermostaboutthelostpaintings? A.Theywerestolenatnight. B.Theywerefoundatlast C.Theysufferedlittledamage D.Thesearchtook14years 3WhenRuegergotthecallfromItalianauthoritieshe. A.quiteexcited B.feltquiterelieved C.plannedtocelebrate D.doubtedthenews 4WhatdoesitprobablymeanwhenRuegersaysthetracewentcoldinthe6thparagraph? A.Ruegergraduallylostinterestinthesearch B.Thenumberoffalsecallswasgreatlyreduced C.Ruegerfeltcoldbecauseoftoomanyfalsecalls D.Thechancetofindthepaintingsbecameslim
Organicfoodisverypopularthesedaysbutcanalsobeveryexpensive.Parentsofyoungchildrenandevensomepetownerswillpayhighprices1organicfoodiftheythinkit'shealthierthannon﹣organicfood.Butmanyothersthinkorganicfoodisjust2wasteofmoney. Thereisonemain3differbetweenorganicandnon﹣organicfood.Organicfarmsdonotuseagriculturalchemicalssuchaspesticides杀虫剂thatstopinsectsfromdamagingcrops. Inmany4countryfoodsthatclaimtobeorganicmusthavespeciallabelsthatguaranteethey6groworganically. Somepeoplethinkorganicalsomeanslocallygrownand6originalthiswastrue.Atfirstonlysmallcompaniesproducedtheseproducts.Butlaterbigfoodcompaniesalsobegansellingorganicproducts.Smallorganicfoodcompaniesfounditdifficult7competewiththesebigcompaniesandmanydidn'tstayinbusinessmuch8long. Manyfarmersandconsumersbelieveorganicfoodissaferandmorenutritious.Theythinkagriculturalchemicalscancauseseriousillnesseslikecancer9thereisn'tmuchevidenceprovingthisistrue.Howeverrecentstudieshaveshownthateatingorganically﹣gownproduce10reduceyourchancesofdevelopingheartdisease.Thereforeweshouldbebettersafethansorrywhenitcomestowhatweeat.
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.每处错误仅涉及一个单词的增加刪除或修改. 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. Rosedevelopedastrangeseriousdiseaselastyear.Herpoorlyfamilycouldn'tpaysomuchmoneyforhertreatment.IntheafternoonofFebruary28ththeStudentsUnioninourschoolholdsanactivitytoraisesomemoneyforher.Althoughitwasalittlebitcoldthatday.manyteachersorstudentscametotheplayground.Theyputtheirmoneyinthecollectionbox.whichwasmadeofbysomestudents.WhotouchedusmostwasthatsomestudentsdonatedallourluckymoneytoRose.Finallyweraised10000yuanintotal.WhenwesentthemoneytoRose'shousefollowingdayRosetogetherwithherparentswasverygrateful.WithtearinhereyesRosesaidshewouldrepaythosewhohadhelpedherafterrecoveredfromherillness.
如图在直线坐标系xOy中从原点处向+y方向同时发射出大量比荷为＝1.0×104C/kg的带负电粒子粒子的初速度大小广泛分布于零到v0＝1.0×104m/s之间．已知这些粒子此后所经磁场的磁感应强度大小为B＝1.0T方向垂直于纸面所有粒子都沿+x方向经过b区域都通过点M30且沿y轴负方向．不计粒子的重力及粒子间的相互作用． 1判断磁场方向 2求速度为1.0×104m/s的粒子从O点运动到M点所用的时间 3通过计算求出符合要求的磁场范围的最小面积．
1某实验小组要对未知电阻Rx进行测量．他们先用多用电表欧姆档进行粗测若多用电表的电阻档有三个倍率先用×10档测量电阻Rx时操作步骤正确发现表头指针向右偏转角度过大为了较准确地进行测量应换到档填“×1”或“×100”．换档后应先填缺少的步骤之后用表笔连接待测电阻进行测量由表盘刻度读得该电阻的阻值是Ω． 2为准确测量该电阻阻值备有以下器材 A．电源电动势约3V内阻未知 B．电压表量程3V内阻无穷大 C．电阻箱最大阻值99.9Ω D．电键单刀单掷开关2个导线若干 该同学进行了如下操作 首先断开电键S2闭合电键S1调节电阻箱使电压表有一合适的读数U记下此时电阻箱的阻值R1接着闭合电键S2调节电阻箱使电压表读数仍为U记下此时电阻箱的阻值R2由此测得电阻Rx＝． 3测出电阻后该同学发现此电路还可以测出电源电动势E和内阻r．闭合电键S1S2调节电阻箱R读出多组R和U的数值并作﹣图象如图2所示该图线斜率为k纵轴截距为a．由此得出电源电动势E＝内阻r＝．
如图所示理想变压器原线圈和副线圈上接有阻值均为R的电阻R1R2原线圈接电压有效值为U的交流电源．现通过滑片P改变原线圈的匝数使原线圈和副线圈接人电路的匝数分别为n1n2则下列说法正确的是
STOCKHOLM.Oct.2Xinhuanet.comThe2018NobelPrizeinPhysicshasbeenawardedtothreescientistsworkingthefieldoflaserphysicstheRoyalSwedishAcademyofSciencesannouncedhereonTuesday. HalfoftheawardforgroundbreakinginventionsinthefieldoflaserphysicswenttoAmericanArthurAshkinandtheotherhalfwasawardedjointlytoFrenchmanGerardAlbertMourouandCanadianDonnaStrickland. Stricklandsaidinatelephoneinterviewwiththeacademyatapressconferencethatshewashappyandsurprisedtobereceivingtheprize.Commentingonherachievementssheemphasizedhowshetriestothinkoutsideofthebox. Ashkininventedopticaltweezers光学镊子thatgrabparticlesatomsvirusesandotherlivingcellswiththeirlaserbeamfingers.ThisnewtoolallowedAshkintorealizeanolddreamofsciencefictionusingtheradiationpressureoflighttomovephysicalobjects.Hesucceededingettinglaserlighttopushsmallparticlestowardsthecenterofthebeamandtoholdthemthere.accordingtothestatement. MourouandStricklandpavedthewayfortheshortestandmostintenselaserpulses激光脉冲evercreatedbymankind.Theysucceededincreatingultrashorthigh﹣intensitylaserpulseswithoutdestroyingtheamplifying放大的material.Theirrevolutionaryarticlewaspublishedin1985andwasthefoundationofStrickland'sdoctoralarticle. StricklandandMourou'snewlyinventedtechniquecalledCPAsoonbecamestandardforhigh﹣intensitylasers.Itsusesincludethemillionsofcorrectiveeyesurgeriesthatareconductedeveryyearusingthesharpestoflaserbeams.Thestatementsaidtherearestillinnumerableareasofapplicationthathavenotyetbeencompletelyexplored. Ithinkit'sreallynicethatDonnaStricklandasafemalescientistgottheprizethisyear.Andit'salsoagoodsignaltoyoungpeoplethatyoucandosomethingveryimportantveryearlyinyourcareerEvaLindrothemphasizedwhoisamemberoftheClassforPhysicsattheRoyalSwedishAcademyofSciences. IhopemorefemalescientistscanwinNobelscienceprizesinfuture.Therearemoreandmorewomenscientists.soIthinkitmaledominancewillchangeandmorefemalescientistsareleadingresearchgroupsandplayingabiggerroleLindrothadded. 1WhatdoesStricklandmeanbysayingtriestothinkoutsideofthebox? A.ShehasneverexpectedtoreceivetheNobelPrize B.Shehastakengreatpainstogettheachievement. C.HerachievementismainlyduetoherpartnerMourou D.Shealwaysthinksofcreativewaysofdoingresearch. 2Whatcanweknowabouttheinventionsoflaserphysics? A.Itwilltakealongtimetoputthemintouse. B.Theywillmakegreatcontributionstoeyeoperations. C.Theyareaimedtorealizeanolddreamofsciencefiction. D.MourouandStrickland'sinventiongrewoutofStrickland'sdoctoralarticle 3Whatcanweinferfromthepassage? A.StricklandisthefirstfemalescientisttowintheNobelPrize B.Thethreescientistsawardedarejointinventorsoflaserphysics CStrickland'ssuccessmeansfarbeyondtheinventedtechniqueitself D.Maledominancewillchangetheleadingpositionoffemalescientists 4Whatisthemainideaofthepassage? A.Laserphysicsisbeingusedinalotofareas B.FemalescientistswillwinmoreNobelPrizes C.Threescientistsshare2018NobelPrizeinPhysics D.Thewinnersaregoodexamplestotheyoungpeople.
如图所示为xOy平面直角坐标系在x＝a处有一平行于y轴的直线MN在x＝4a处放置一平行于y轴的荧光屏荧光屏与x轴交点为Q在第一象限内直线MN与荧光屏之间存在沿y轴负方向的匀强电场．原点O处放置一带电粒子发射装置它可以连续不断地发射同种初速度大小为v0的带正电粒子调节坐标原点处的带电粒子发射装置使其在xOy平面内沿不同方向将带电粒子射入第一象限速度与x轴正方向间的夹角为0≤θ≤．若在第一象限内直线MN的左侧加一垂直xOy平面向外的匀强磁场这些带电粒子穿过该磁场后都能垂直直线MⅣ进入电场．已知匀强磁场的磁感应强度大小为B带电粒子的比荷＝电场强度大小E＝Bv0不计带电粒子重力求 1粒子从发射到到达荧光屏的最长时间 2符合条件的磁场区域的最小面积 3粒子打到荧光屏上距Q点的最远距离．
It'sabighammertocrackanut.Thisishowoneangryparentdescribedtherecentcrackdown严厉的打击byLondonpoliceonparentswhodroptheirkidsoffatschoolbycar.Yesyoureadthatcorrectly﹣theverymode模式oftransportationthatmanyAmericanschoolsinsististheonlysafewaytodeliverkidstoschoolisnowconsideredillegalintheUK. ThedecisiontofineanyvehiclesseendroppingofforpickingupkidswithinaparticularzoneofeastLondoncomesfromcitycouncilors'议员long﹣termeffortstomaketheareasaferandlesscrowded.Theysaythey'vebeentryingforyearstoencouragereasonableparkingbutinvain.Neighborhoodresidentscomplainfrequentlyabouttheirdrivewaysbeingblockedbyillegallyparkedcarsfor15minutesormoreoftenwhilethey'retryingtogettoworkandthestreetsarelongovercrowded. Nowtheruleshavechanged.Someparentsareangry.Angieisamotherwhomadethebighammercommentandsaysthecrackdowniswayoverthetop.Thenearestdrop﹣offpointforhersix﹣year﹣oldisnowafive﹣minutewalkfromtheschool.Othersarehappywiththedecisionseverethoughitmayseem. CouncilorJasonFrostsaidTraffichasbeenclearlyreducedandmorechildrenarenowwalkingtoschoolwhichisagreatoutcome.Iwouldratherhavecomplaintsthatweareslightlyinconveniencingparentsthanhearthatachildhadbeenseriouslyinjuredbecausenothingwasdone. Iwitnessdailythechaoscreatedbythesein﹣towndriverswhenIwalkmyownkidstoschool.There'saparkinglotcrowdedwithvehiclesandaslow﹣movingtrainofcarsmovingincirclesmanyfillingtheairwithharmfulsmoke.Meanwhiletheconversationsaroundoverweightchildrenandtheimportanceofdailyphysicalactivitiescontinuetostandoutinschools. 1WhyisAngieopposedtothenewrule? A.SheisoftenfinedbyLondonpolice. B.Shewillloseherjobasaschooldriver. C.ShehasadaptedtotheAmericanpractice. D.Shethinksitaddsinconveniencetoherkid. 2WhathasledtothenewrulebeingmadeaccoringtoJasonFrost? A.residents'complaints. B.students'healthproblem. C.safetyconcern. D.airpollution. 3Whatcanbeseenafterthecrackdowniscarriedout? A.Lessdailychaos. B.Supportfromallpeople. C.Moreoverweightchildren. D.Complaintsfromneighbors. 4Whatisthemainideaofthetext? A.Parentsattempttoresistaschoolrule. B.Londonpolicecausewidespreadanger. C.Americanschoolscaremoreaboutkids'safety. D.Differentvoicesareheardonanewtrafficpolicy.
某玻璃材料制成的光学元件截面如图所示左边是半径为R的半圆右边是直角三角形CDE∠DCE＝60°．A点发出一细光束从B点射入元件后与AO平行O为半圆的圆心CD为直径AO与CD垂直．已知玻璃的折射率为B点到AO的距离为R光在真空中的光速为c．求 i入射光线AB与AO夹角α ii光线从B点射入元件到第一次射出元件所需的时间．
某厂家为了测试新款汽车的性能将两辆完全相同的汽车并排停在检测场的平直跑道上tl＝0时刻将两车同时启动通过车上的速度传感器描绘出了两车的速度随时间变化的规律图线如图所示．已知图象中两阴影部分的面积S2＞S1则下列说法正确的是
在△ABC中角ABC所对应的边分别为abc且满足＝•＝3． Ⅰ求△ABC的面积 Ⅱ若b+c＝6求a的值．
假定你是李华本来约好周六要带你的外国朋友Toby去看京剧PekingOpera可你要代表本班参加英文演讲大赛而不能赴约请你给他写封邮件表达歉意. 写作要点1.解释不能按时赴约的原因 2.重新安排时间并给他推荐一两个周末休闲活动. 注意1.词数100左右 2.可以适当增加细节以使行文连贯.
Exerciseisanimportantpartofkeepingahealthylifestyle.Fitnesstoolsandtipscanhelpindividualsdevelopanexerciseplanthatisnotonlysafebuthelpsthemtoworktowardacertaingoalsuchasweightlossorrunningamarathon. ConsultYourDoctor Beforebeginningtheweightlossorexerciseprogramitisbesttoconsultyourdoctortomakesurethatyouareinproperhealthandthattherearenopossibleconditionsthatcouldgetworsebyexercise.Askyourdoctortorecommendexercisesbasedonyourfitnesslevelthatwillhelpyouachieveyourgoals. SetGoalsandLimits Whenbeginningafitnessprogramitisimportanttostartoffslowandworktowardamoreadvancedgoal.Beginwithshort10﹣to20﹣minuteexerciseeachdaytoprepareyourbodyformoreactiveexercisesandtopreventinjury. DrinkPlentyofWater Duringexercisethebodylosesliquidfromsweatingthereforeitisimportanttodrinklotsofwaterbeforeduringandafterexercising.Expertsrecommenddrinkingwaterorsportsdrinksevery15to20minutesduringexerciseandmoreoftenduringmoreactiveexercises.Continuetodrinkwaterseveralhoursafterexercisingtorefillliquidsinthebody. ExerciseEquipment Exerciseequipmentsuchastreadmills跑步机exercisebikesandweightsisagreatwaytostayfitwhenonabusyscheduleoronrainydays.Beforeusingexerciseequipmentathomeorinthegymeducateyourselfontheproperuseofeachpiecetoavoidinjurytoyourselfordamagetotheequipment. TrackingTools Useoftoolssuchaspedometers计步器orheartratemonitorscanhelprecordcaloriesstepsandheartrate.Thesetoolscanhelpkeepdietersandathletesactiveandeagertoreachtheirhealthandfitnessgoals. 1What'sthemainpurposeofthepassage? A.Tointroducesomewaysofexercising. B.Tointroduceussomeexercisetipsandtools. C.Topersuadeustotakeexercisetokeepfit. D.Togiveusadviceonlosingweightbyexercise. 2WhichofthefollowingisTRUEaccordingtothepassage? A.Youcanloseweightortakeexerciseinpoorhealth. B.Treadmillsareonlyusedinthegymwhenitrains. C.Startingwithlongandviolentexercisemaycauseinjury. D.Youneedtodrinklotsofwateruntilyoufinishexercising. 3Howoftenshouldwedrinkwaterduringextremeactiveandviolentexercises? A.Every10minutes. B.Every15minutes. C.Every20minutes. D.Every30minutes.
如图所示两端封闭的粗细均匀且导热性能良好的玻璃管放置在水平桌面上玻璃管长度为3L单位cm玻璃管内由长度为L单位cm的水银柱将管内的理想气体分成左右两部分稳定时两部分气体长度相同左右两部分气体的压强均为HcmHg．现在外力作用下使玻璃管沿水平桌面向右做匀加速直线运动玻璃管中左侧的气柱长度变为原来的一半重力加速度为g求玻璃管运动的加速度a的大小．
Beth.justonemoresaidmynurseMary.Ihadjustmadeanothersit﹣up仰卧起坐red﹣facedand1andthenfellbackontothemat.Maryleanedovermewaitingformeto2myarmandgiveherfive击掌相庆. Icant.Isaid.Givemeaminute.IwonderedagainhowIhadgottentothis3.Fivesit﹣ups?Icouldbarely4itwithouthavingtorestnow.Whathad5thegirlwhooncecouldevenswimandrun?Yourformerselfis6.Marysaid.Whoeveryouwereconcentrateonbeingwhoyou'renow.ButIcouldn't.Ihatedthediseasethatcausedmy7.Itevenmadewalkingupstairsahardthing. WithasighIpushedupwithonearmand8drewmyselfintoaseatedposition.I9outandgaveMaryahighfive.ShesmiledatthefactthatIwasstill10IhatewhoI'mnowIsaid.Beth.shesaidgently.Fitnessisn'tan11.Youjustneedtocompareyourselfwithyourself.Ifyoucoulddofivesit﹣upstodaydosixtomorrow.Iknewwhatshesaidwasto12me. Anywaythatdaywe13thesessionquitewellandItookher14toheartinthecomingdays.Onhotdays.ashort15couldmakemesweatasifIhadgoneforalongjog.YeteverytimeIwantedto16IsaidJustonemore. NowthatI'veadjustedtolife.thererefewdayswhenI'm17withhowmuchIcantdo.OccasionallywhenIwatchsomeonedanceorrunandcan'thelpbut18myselftohimorherI'llthinkofthewordsthatIonlyneedtothinkaboutmyself﹣imaynotbeas19asothersbutI'mstill20todoingjustonemoreofwhateverIneedtodo. 1A.exhausted B.encouraged C.excited D.amazed 2A.drop B.bend C.wave D.lift 3A.answer B.area C.point D.truth 4A.get B.make C.resist D.take 5A.happenedto B.broughtup C.letdown Dsettleddown 6A.subjective B.tough C.gone D.sympathetic 7A.regret B.weakness C.shame D.unemployment 8A.eventually B.suddenly C.actually D.seldom 9A.worked Bslipped C.stepped Dreached 10A.striking B.waiting C.struggling D.learning 11A.achievement B.competition C.advantage D.goal 12A.treat B.believe C.embarrass D.push 13A.gotonwith B.madeupfor C.putaside D.figuredout 14A.warning Bcommand C.advice D.blame 15A.break B.sleep C.speech D.walk 16A.run Bresign C.hurt D.quit 17A.stuck B.connected C.filled D.occupied 18A.add B.compare C.relate D.attach 19A.outgoing B.brave C.strong D.optimistic 20A.equal Bcommitted C.close D.open
已知函数fx＝|x+a|+|x﹣2|． I当a＝﹣3时求不等式fx≥3的解集 II若fx≤|x﹣4|的解集包含[12]求a的取值范围．
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