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已知实数x，y满足约束条件，则z=2x-3y的最大值为（ ）
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NaClO2常用来漂白织物其漂白能力是漂白粉的4～5倍NaClO2也是一种重要的杀菌消毒剂．工业上生产NaClO2的一种工艺流程如图所示 1ClO2发生器中的产品之一是NaHSO4在该发生器中所发生反应的离子方程式为． 2反应结束后向ClO2发生器中通入一定量空气目的是． 3吸收器中发生反应的化学方程式为．吸收器中要用冷的NaOH溶液和H2O2溶液吸收ClO2原因是． 4将ClO2通入食盐水中用情性电极电解也可以制得NaClO2产品．阳极的电解产物是填化学式阴极的电极反应式为． 5相同条件下1molNaClO2与gCl2的氧化能力相当．
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G对羟基苯乙酸是合成某治疗高血压药物的中间体．一种由芳香烃A制备G的合成路线如图所示． 请回答下列问题 1A的名称为． 2试剂M是．B→C的反应类型是． 3E的结构简式为．F中含有官能团的名称是． 4写出D→E反应的化学方程式． 5H是G的同分异构体且满足下列条件①与FeCl3溶液发生显色反应②核磁共振氢谱有5组峰峰面积之比为12221．请写出3个符合条件的H的结构简式． 6苯甲酸可用于染料载体香料及增塑剂等的生产．参考题目中的有关信息设计由苯制备苯甲酸的合成路线无机试剂自选．
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如图所示在x＝0处的质点O在垂直于x轴方向上做简谐运动形成沿x轴正方向传播的机械波．在t＝0时刻质点O开始从平衡位置向上运动经0.4s第一次形成图示波形P是平衡位置为x＝0.5m处的质点．①位于x＝5m处的质点B第一次到达波峰位置时求位于x＝2m处的质点A通过的总路程．②若从图示状态开始计时至少要经过多少时间PA两质点的位移y坐标才能相同
10分 ApologizingtheRightWaytoaFriend Whyareapologiessodifficult?Sayingyouaresorrycanbeoneofthemostdifficultthingsyoudo.Butweallmakemistakessoyou'llprobablyhaveanoccasionwhenyouneedtoapologize. Perhapsyouhadabigblowupandrealizedlateryoureactedpoorly.1Whateverthereasonapologizingcanhelpyoubothhealandmoveonfromthesituation. 2Firstyouacknowledgethatyoudidsomethingwrong.Withanapologyyoutakeresponsibilityforyouractionswhichallowsyourfriendtoforgiveyou.Secondanapologygivesyousincerityasafriend.3butthatdoesn'tmeanyoustillshouldn'tapologize. Nowwhatareelementsofaproperapology?4dependingonwhattheoffensewaswhereitwasdoneandwhoyouareapologizingto.Ingeneralagoodapologyshouldincludethefollowingarequestfortheirattentionanacknowledgmentofwhathappenedsincerityinadmittingyoudidsomethingwrongandthewords.I'msorryorIapologize. Herearethingsnevertosaywhenapologizing.Notethattheartofapologizinginvolvestakingresponsibility.Neverapologizeasawaytoshutsomeoneupwhentheyaresayingyouhurttheirfeelingsandyoudon'tthinkyoudid.5youshouldtalkthingsthroughwithyourfrienduntilyouseewhytheyarehurtorhowyoucameacross.You'llreallyneedtoself﹣reflectsoyoucanseethingsfromyourfriend'spointofview. A.Whenyoumakeyourapologyinperson B.Ifyoureallybelieveyoudidnothingwrong C.Apologiesbenefitfriendshipsinavarietyofways D.Thewayyouapologizeisgoingtobeslightlydifferent E.Ormaybeyoujustdidn'tshowsupportwhenyouneededto F.Apologizingtherightwayhowevermaytakealittlepractice G.Sometimesourpalsforgiveuseasilyfortheminorthingswedowrong
8分Haveyoueverheardofagritourismwhereyoucanexperiencefarmlife?IfnotDr.CindyAyers﹣ElliottwilltellyoutherealstoryofFootPrintFarms. TheoriginalconceptofbuildingFootPrintFarmswassimple.WhenAyers﹣Elliottreturnedtoherhometownaftergraduationshedidn'thavetolookanyfurtherthanherstate'salarminghealthstatisticstofindamission.Everywheresheturnedtherewerereportsofhighbloodpressurediabetesobesityandheartdisease.Theproblemwasalreadyidentified.explainsAyers﹣Elliott.ToomanyMississippianswereseriouslyunhealthyanditdidn'ttakeresearchtoseethat.Andmanyofthestate'sgreatesthealthchallengescoulddirectlyresultfrompoordiet. ThesedaysFootPrintFarmswhichstartedwithafewraisedbedsofherbsandvegetablesismakingfreshnaturallygrownfood.Whenspeakingofthekeytomysuccesstheco﹣opmodelworksbecausewesharetheworkandrewardsnotesAyers﹣Elliott.AperfectexampleistheWingfieldHighSchoolfootballteam.Toearnthemoneyforequipmentandotheritemsplayerscommittedtoworkingfivehoursaweekonthefarmandbytheendofthesummertheyhadproduced1000melonsandtheprofitsfromtheirsaleshelpedtobuyweightsT﹣shirtssweatsuitsandpregamemeals.Butthelessonstheylearnedabouttherewardsofhardworkandworkingtogethertoaccomplishsomethingwereevenmorevaluableproductsoftheirefforts. It'samodelthatcaneasilybelearnedinotherplacesandI'mlookingforwardtoseeingsomeofourcurrentpartnersdojustthat﹣﹣totakewhattheyhavelearnedhereandspinitoffinothercommunitiesAyers﹣Elliottremarks.Sheisnowlookingforwardtodevelopinganagritourismaspecttothefarmwherevisitorscanexperiencefarmlifelearnnewskillsandtakewiththemseedsofinspirationtheycansowintheirowncommunitieswhentheyreturnhome. 1WhatmadeAyers﹣ElliottsetupFootPrintFarms? A.Theproblemsfacedbylocalfarmers. B.Herfurtherresearchintoheartdisease. C.Thefailureofhercareeraftergraduation. D.Thehealthstateofpeopleinherhometown. 2Whydoestheauthortakethefootballteamasanexample? A.Toadvocatetheconceptofindependence. B.Tostresstheimportanceofteamwork. C.Tosupporttheideaofco﹣opmodel. D.Toexplorethekeytosuccess. 3WhatisAyers﹣Elliott'sattitudetowardsthefutureofFootPrintFarms? A.Optimistic. B.Skeptical. C.Cautious. D.Ambiguous. 4Whatisthemainideaofthetext? A.Naturallygrownfoodbenefitspeople'shealth. B.FoodPrintFarmsismakingadifferenceinMississippi. C.Ayers﹣Elliottencouragespeopletoexperiencefarm D.AgritourismisbecomingincreasinglypopularinAmerica.
用NA表示阿伏加德罗常数的值下列说法正确的是
如图为模拟远距离输电的部分测试电路．ab端接电压稳定的正弦交变电源定值电阻阻值分别为R1R2且R1＜R2理想变压器的原副线圈匝数比为k且k＜1电流表电压表均为理想表其示数分别用I和U表示．当向下调节滑动变阻器R3的滑动端P时电流表电压表示数变化分别用△I和△U表示．则以下说法正确的是
某同学测定电源电动势和内阻所使用的器材有待测干电池一节内阻很小电流表A量程0.6A内阻RA小于1Ω电流表A1量程0.6A内阻未知电阻箱R10～99.99Ω滑动变阻器R20～10Ω单刀双掷开关S单刀单掷开关K各一个导线若干． 1该同学按图甲所示电路连接进行实验操作．请在答题卡相应位置的虚线框内补全与图甲对应的电路图． 2测电流表A的内阻闭合开关K将开关S与C接通通过调节电阻箱R1和滑动变阻器R2读取电流表A的示数为0.20A电流表A1的示数为0.60A电阻箱R1的示数为0.10Ω则电流表A的内阻RA＝Ω． 3测电源的电动势和内阻断开开关K调节电阻箱R1将开关S接填“C”或“D”记录电阻箱R1的阻值和电流表A的示数断开开关K开关S所接位置不变多次调节电阻箱R1重新实验并记录多组电阻箱R1的阻值R和电流表A的示数I． 4数据处理图乙是由实验数据绘出的﹣R图象由此求出干电池的电动势E＝V内阻r＝Ω．计算结果保留二位有效数字 5如果电流表A的电阻未知本实验填“能”或“不能”测出该电源的电动势．
如图所示一足够长的木板在光滑水平面上以速度v向右匀速运动现将质量为m的物体竖直向下轻轻地放置在木板上的右端已知物体和木板之间的动摩擦因数为μ．为保持木板的速度不变须对木板施一水平向右的作用力F．从物体放到木板上到它相对木板静止的过程中木块与物体组成的系统产生的内能为
如图所示间距为L的水平平行金属导轨上连有一定值电阻阻值为R两质量均为m的导体棒ab和cd垂直放置在导轨上两导体棒电阻均为R棒与导轨间动摩擦因数均为μ导轨电阻不计最大静摩擦力等于滑动摩擦力整个导轨处在竖直向下的匀强磁场中磁感应强度为B．现用某一水平恒力向右拉导体棒ab使其从静止开始运动当棒ab匀速运动时棒cd恰要开始滑动从开始运动到匀速的过程中流过棒ab的电荷量为q重力加速度为g求 1棒ab匀速运动的速度大小 2棒ab从开始运动到匀速运动所经历的时间是多少 3棒ab从开始运动到匀速的过程中棒ab产生的焦耳热是多少
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