已知方程ax+y=3x-1是二元一次方程，则a满足的条件是（　　）A．a≠0 B．a≠-1 C．a≠3 D．a≠1

甲乙两个实心均匀正方体放在水平面上它们的质量相等密度关系是ρ甲＞ρ乙当在甲乙两物块上分别放重为G1G2的物体时两物块对水平面的压强相同或分别施加竖直向上的力F1F2均小于物块重力时两物块对水平面的压强也相等则G1与G2F1与F2的大小关系是

如图是家庭常用插线板．插线板上的指示灯在开关闭合时会发光插孔正常通电如果指示灯损坏开关闭合时插孔也能正常通电选项中主要元件间连接方式正确的是

为了使教师内的学生免受到环境噪声的干扰下列方法中最合理有效的是

关注健康预防疾病．下列叙述错误的是

为测定某BaCl2溶液的溶质质量分数进行如下实验取104g该溶液于烧杯中加入1g稀硝酸溶液酸化无任何现象然后将30g一定溶质质量分数的硫酸溶液分三次加入每次充分反应后过滤称量实验中物质的质量损失忽略不计数据如表 根据以上数据计算BaCl2+H2SO4═BaSO4↓+2HCl 1该实验过程中产生沉淀的总质量为g． 2该BaCl2溶液中溶质的质量分数写出计算过程

2018年2月6日现役世界最强大运载火箭猎鹰重型从美国佛罗里达州肯尼迪航天中心39A发射台腾空而起拖着熊熊尾焰直入蓝天．这预示着人类探索宇宙更近了一步．火星Mars是太阳系八大行星之一是太阳系由内往外数的第四颗行星属于类地行星直径约为地球的53%火星直径约为月球的两倍地球的一半表面重力约为地球的2/5．火星周围也笼罩着大气层与地球大气层相似．火星大气层的主要成分是二氧化碳其次是氮氩此外还有少量的氧和水蒸气．下列说法科学的是

ItissaidthatEnglishhasbecomethelanguageofinternationaltradeandtransport.Mostpilotsinplanestravelingfromonecountrytoanotheruseittotalkwithairports.Allshipssailingontheoceanscallforhelpbyradioinit.Ithasbeensaidthat60percentoftheworld'sradiobroadcastsand70percentoftheworld'smailuseEnglish.AtinternationalsportsmeetsatmeetingsofscientistsfromdifferentcountriesandattalksofwritersandartistsfromthecornersoftheearthEnglishisthelanguagemostcommonlyused. Englishhasinfactbecomethelanguageofinternationalcooperationinscienceandtechnology.Themostadvancedresultsinspacenuclearandcomputerresearcharepublishedinit.AscientistwhospeaksandwritesEnglishisinclosertouchwiththescientistsinothercountriesthanonewhodoesn't. 1WhydopeoplesayEnglishhasbecomethelanguageofinternationaltradeandtransport? A.Mostpilotsuseitwhileflying. B.Shipsontheseacallforhelpinit. C.Itiswidelyusedatworldsportsmeets. D.Alltheabove. 2Itcanbeinferred推理推断that. A.itisnotnecessaryforustolearnChinese. B.Englishisamustifyouwanttoknowthenewestdevelopmentinspacenuclearandcomputerresearch. C.Chineseisalsousedatinternationalsportsmeets. D.mostplane﹣flyersuseEnglishbecauseitiseasytolearn. 3Ifyouareattendinganinternationalconferenceontechnologyresearchyouwillprobablyhearmostattendersspeaking. A.aspecialinternationallanguage B.Chinese C.English D.aEuropeanlanguage

在中与是同类二次根式的是

为了探究物体所受重力与质量的关系某实验小组进行了实验．1钩码所受重力的大小用进行测量测量时钩码必须处于状态．2他们将测出的数据记录在如下表格中并进行了处理通过分析发现有一次测量数据存在问题这个数据是重新测量并进一步分析数据得出的结论是．

智能手机是一种多功能通讯工具一款智能机通常含有41种以上的化学元素．手机屏幕部分用的是硅酸铝玻璃下列关于硅酸铝玻璃性质的推测正确的是

要除去下列物质中的少量杂质括号内物质为杂质下列实验方案设计中不合理的是

下列符号中表示两个氢原子的是

WhoeverhasmadeavoyageuptheHudsonRivermustremembertheCatskillMountains.TheyareabranchofthegreatAppalachianfamilyandcanbeseentothewestrisinguptoanobleheightandtoweringoverthesurroundingcountry.Whentheweatherisfairandsettledtheyareclothedinblueandpurpleandprinttheirbeautifulshapesonthecleareveningskybutsometimeswhenitiscloudlessgraysteamgathersaroundthetopofthemountainswhichinthelastraysofthesettingsunwillshineandlightuplikeacrownofglory. Atthefootofthesemountainsatravelermayseelightsmokegoingupfromavillage. Inthatvillageandinoneofthehouseswhichtotelltheexacttruthwassadlytime﹣wornandweather﹣beatentherelivedmanyyearsagoasimplegood﹣naturedfellowbythenameofRipVanWinkle. Rip'sgreatweaknesswasanaturaldislikeofallkindsofmoney﹣makinglabor.Itcouldnotbefromlackofdiligenceforhecouldsitalldayonawetrockandfishwithoutsayingawordeventhoughhewasnotencouragedbyasinglebite.Hewouldcarryagunonhisshoulderforhourswalkingthroughwoodsandfieldstoshootafewbirdsorsquirrels.Hewouldneverrefusetohelpaneighborevenintheroughestwork.Thewomenofthevillagetoousedtoemployhimtodosuchlittlejobsastheirlesshelpfulhusbandswouldnotdoforthem.InawordRipwasreadytoattendtoeverybody'sbusinessbuthisown. Iflefttohimselfhewouldhavewhistledlifeawayinperfectsatisfactionbuthiswifewasalwaysmadathimforhisidleness懒散.Morningnoonandnighthertonguewasendlesslygoingsothathewasforcedtoescapetotheoutsideofthehouse﹣﹣theonlysidewhichintruthbelongstoahenpeckedhusband. 1WhichofthefollowingbestdescribestheCatskillMountains? A.TheyareonthewestoftheHudsonRiver. B.Theyareveryhighandbeautifulinthisarea. C.TheycanbeseenfromtheAppalachianfamily. D.Theygatherbeautifulcloudsinblueandpurple. 2Theheroofthestoryisprobably. A.hard﹣workingandlikesallkindsofwork B.idleandhatesallkindsofjobs C.simpleidlebutverydutiful D.gentlehelpfulbutalittleidle 3Theunderlinedwordshenpeckedhusbandinthelastparagraphprobablymeansamanwho. A.likeshunting B.isafraidofhens C.loveshiswife D.isafraidofhiswife 4Whatwouldbethebesttitleforthetext? A.CatskillMountains. B.AMountainVillage. C.RipVanWinkle. D.ADutifulHusband.

下列相关的量之间的关系符合如图所示图线的是

Ittakesplentyoftimeforsomeadultstotrytostopchildrenplaying.Theyareusuallypeoplewhothinkofplayasbeingthe1ofworkandthereforeawasteoftime.Forhumansworkisawayofgettingfoodtoeatandlikehumans2mustspendtimedoingthe3things.Regardlessofthischildren4playingandsodootheryounganimals.Itisquite5tokeepbothasmallchildandayoungcat6forhourswithapieceofpaper. Huntingmaybethemostobviousskill7inplaybutitisfarfrombeingtheonlyone.Lambsandgoatkidsplay8althoughasadultstheywillnever9anythingotherthansomegrass.Butfortheseyounganimalstoo10isanimportantpartoflearning.Sheepandgoatsare11hillandmountainanimals.Runningandskippingexerciseyounglegsanddevelopastrongsenseof12thatwillkeepthemsafeonthesteepestrocks. 13animals'playchildren'splayisnotsodifferent.14treesandcatchingfliesarenotthemostobvioustrainingfortheadultworldbuttheflexibility15intheseactivitiesissimilartothatrequiredofabusdriverorbusinessman. Whatweknowaboutanimalsshowsusthatplayingisaverygoodwayof16somaybeoneofthebestwaysfor17tolearnisalsobyplaying.Childrenfindplayingisfunbut18noticethattheyarealsolearningatthesametime.Mostpeoplecontinuetoplaygameslongaftertheyhavebecome19andperhapsthatisbecausewerelysomuchonour20tolearn. 1A.reward B.basis C.nature D.opposite 2A.children B.animals C.parents D.cats 3A.dull B.ordinary C.same D.chief 4A.enjoy B.regret C.delay D.ignore 5A.necessary B.possible C.reasonable D.difficult 6A.annoyed B.alarmed C.amused D.amazed 7A.practiced B.kept C.tested D.required 8A.clumsily B.endlessly C.crazily D.aggressively 9A.catch B.plant C.learn D.hunt 10A.play B.work C.jump D.walk 11A.naturally B.initially C.strangely D.equally 12A.direction B.balance C.distance D.space 13A.Basedon B.Inspiredby C.Comparedwith D.Developedform 14A.Cutting B.Growing C.Watering D.Climbing 15A.reduced B.needed C.damaged D.allowed 16A.growing B.exercising C.improving D.learning 17A.humans B.creatures C.adults D.students 18A.generally B.possibility C.hardly D.truly 19A.strong B.wise C.athletic D.mature 20A.flexibility B.liberty C.curiosity D.responsibility

Thespiritofpullingtogethercanalwaysmakeourlearnatlast.win

元素周期表是化学学习的重要工具．请回答下列问题 1元素周期表中列出了元素它们之间最本质的区别是 2如图是镁元素在元素周期表中的信息和镁的原子结构示意图．镁原子的相对原子质量是在化学反应中镁原子易填失去或得到电子由镁元素与氯元素组成化合物氯化镁的化学式为．

函数y=ax2+bx+c的图象如图所示那么关于x的方程ax2+bx+c﹣4=0的根的情况是

已知某两种物质在光照条件下能发生化学反应其微观示意图如图一种小球代表一种原子．下列说法不正确的是

我国自主生产的某型号水陆两栖坦克如图所示．它的总质量为2.2×104kg停在水平地面上时履带着地的总面积为4m2．海水的密度ρ＝1.03×103kg/m3求 1该坦克停在水平地面上时对地面的压强 2该坦克在海面上航行时受到海水的浮力 3若该坦克用2.8×103N的推进力在水平地面上以15m/s的速度匀速行驶10min推进力所做的功和功率．

水是生命之源下列关于水的叙述不正确的是

如果物体离凸透镜22厘米时能在光上屏上得到一个清晰的倒立缩小的像则下列判断正确的是

汉代一些墓室祠堂里有雕刻着画像的石头．现有一块汉画像石质量为500kg体积为0.2m3g取10N/kg．求这块汉画像石受到的重力．

下列变化过程中主要发生物理变化的是

Moreandmorepeoplekeeppetsnowadays.Thedogandthecatarelovablebeautifulandintelligentanimals.Adogandacatcanteachusalotabouthumannature.Morethanoneownerofadoghassaidthattheanimalunderstandseverythinghesaystoit.Soamotherorfatherwhohasevercaredforpetsislikelytobemorepatientandunderstandingwiththeirchildrenaswellandespeciallytoavoidmakingnegativeorruderemarksinthepresenceofchildrennomatterhowyoung. Acatcanteachusavaluablelessonabouthowtobecontentedhowtocalmdownateasehowtositwhereasadogcanteachuslessonsofloyaltyanddevotion.Sothere'splentytobesaidinfavorofkeepingpets.ButwithallthatinmindIstillsaylet'sstopkeepingpets.TobepracticalIamsuggestingthatifwedonotnowhaveapetweshouldnotgetonesecondifwenowhaveapetweletitbeourlastone.Icouldneversaythatpetsarebad.I'msayinglet'sgiveupthisgoodthing﹣theownershipofapet. Thepurchasethehealthcarethefeelingandhousingandtrainingofapet﹣andIchieflymeanthelargerlong﹣livedpets﹣﹣﹣costtimeandmoney.Thecaringofapetcostsfromadollaraweektoadollarormoreaday.Iwouldnotforamomentdenyitisworththat.Butthefactoutsidethewallsofourhomekeepsbreakinginonourawareness.Thoughwedonotseethepoverty﹣strickenpeopleofIndiaandAfricaandSouthAmericawecanneverquiteforgetthattheyarethere.Nowandthentheirfacesareshowninthenewsorinthebeggingadsofrelieforganization.Probablywesendadonationwheneverwecan. Themoneyandthetimewespendonpetsissimplynotourown.Doingwithoutpetsandthensendingthemoneysavedtoarelieforganizationwouldmeansavingalife﹣﹣﹣overtheyearsseveralhumanlives.Togivewhatwewouldspendonacatmightnotfeedachildbutitwouldprobablypayforhismedicalcareorbasiceducation.Thepointneedsnolongerlaboring.Thatisallthatneedstobesaid. 1WhichofthefollowingisTRUEaccordingtothepassage? A.Peopleusuallyspendsomuchmoneyonpetswithoutrewards. B.Peoplehavenomoneytosolvetheproblemofpovertyintheworld. C.Takingcareofpetscanhelpmakeourchildrenandourselveskinder. D.Theauthorcallsonthepeopletostopraisingpetsathomebecauseofdiseases. 2Howaremostpetownersdifferentfromothersaccordingtothepassage? A.Theycanbemoreloyalanddevoted. B.Theytendtobemorepatientandcaring. C.Theyseemtobecontentedandcalm. D.Theyarelikelytobebusyandindependent. 3Whatdoestheunderlinedpartthefactreferto? A.Moreandmorepeopleliketokeepdogsandcats. B.Nobodycaresaboutthepoverty﹣strickenpeople. C.Keepingpetscausesmuchwasteofmoneyandtime. D.Manypeopleoneartharestillsufferingfrompoverty. 4Whatistheauthor'sviewaboutpet﹣keeping? A.Keepingpetscanmakeusunderstandmoreabouthumanandnature. B.Keepingpetsforalongtimemakespeoplefeellackofcommunication. C.Weshouldstopkeepingpetstodonatethemoneytothepoorpeople. D.Wemustkeepallkindsofpetstoprotectmanandenvironmentproperly.

如图所示是电位器结构示意图．电阻片R的两端分别与接线端AC相连滑动片P的一端通过转轴O与接线端B相连另一端与电阻片R接触良好并能绕转轴O在电阻片R上滑动．电阻片R的总电阻为10Ω当滑动片P位于图示的位置时接线端BC间的电阻为6Ω将电位器AB两个接线柱分别接在电压为2.4V的电源两端．则

小蕾同学的实验小组在探究电流产生热量的多少与哪些因素有关时使用了如图甲所示的实验装置烧瓶A内装有一定质量的煤油． 1连接实验电路时同组的小超问小蕾打开实验室里的水龙头就可以接到水了为什们还要用煤油呢小蕾对他说因为煤油的比水的小方便观察温度计示数的变化． 2在闭合开关前他们应将滑动变阻器的滑片P移到最选填左或右端． 3小蕾将滑片P移动到某一位置闭合开关10s后断开开关．在这段时间他们观察到温度计的示数逐渐升高．这个实验现象说明电流通过导体产生热量的多少与有关． 4接着小蕾又将滑片P向左移动到某一位置闭合开关10s后断开开关．他们观察到这一次温度计的示数比上一次实验时的示数还要高．两次实验对比他们能得出的结论是电流通过导体产生热量的多少还与有关． 5完成上述实验后同组的小磊想到家中的电热烤火器工作时烤火器热得烫手但连接烤火器的导线却不怎么热．他猜想电流通过导体产生热量的多少可能还与电阻的大小有关．于是他们准备了两个完全相同的烧瓶烧瓶內装有质量相等初温相同的煤油并将两段长度横截面积相同但材料不同的电阻丝浸没在煤油中再用带有规格完全相同的温度计的橡胶塞封住瓶口如图乙所示． ①图乙中两段电阻丝的连接方式是． ②闭合开关后他们观察到A烧瓶中的温度计示数逐渐升高B烧瓶中的温度计示数不变．出现这种现象的原因可能是B烧瓶中的电阻丝． ③他们排除故障闭合开关一段时间后观察到选填A或B烧瓶内温度计的示数较高．由此可知小磊的猜想是选填正确或错误的．他们通过分析本次实验现象得出了在电流大小和通电时间相同时电阻越大电流通过导体产生的热量越多的结论．

在科学实验中常用到斜面这一简单机械请回答问题 1利用斜面研究阻力对物体运动的影响如图甲所示．小车从同一斜面的同一高度由静止开始滑下在毛巾木板平板玻璃等不同的表面上前进不同的距离后停止此过程中小车克服阻力做功．假设在毛巾木板平板玻璃表面上小车克服阻力做的功分别为W1W2W3请比较并写出它们的大小关系式． 2利用斜面探究动能大小与哪些因素有关如图乙所示．在这个实验中通过观察比较来判断小球动能的大小．要探究动能大小与物体的运动速度应该如何操作．

化学实验室制取气体的部分仪器或装置如图所示请回答下列问题． 1仪器B的名称． 2若用氯酸钾和二氧化锰制取氧气必须要增加的一种仪器是该反应的化学方程式为．若用装置H收集氧气氧气应从填a或b端通入． 3若要组装一台制取并收集二氧化碳气体的装置可选择的装置组合为填字母写一种组合即可． 4某同学用上述2中的方法制取氧气实验过程中试管发生了炸裂请你帮他分析试管炸裂可能的原因是．写一条即可

下列事例中的物态变化过程放热的是

已知NaHCO3在270℃时完全分解为碳酸钠水和二氧化碳而Na2CO3受热不分解．现有某工厂生产出的一批NaHCO3产品中混有少量的Na2CO3某兴趣小组同学为了测定该产品中NaHCO3的质量分数设计了下列两种实验方案． 方案一样品测定生成CO2的质量． 1NaHCO3俗称为本实验采用如图所示的装置C中盛放的物质是． 2若无装置E在其他操作正确的情况下填能或不能准确测定样品中NaHCO3的质量分数． 3在其他操作正确的情况下不能将分液漏斗中的稀硫酸改为稀盐酸的原因是． 方案二样品测定剩余固体质量 具体操作步骤如下 ①一只洁净的坩埚称得质量为21.2克再向其中加入样品称得总质量为41.2克 ②加热盛有样品的坩埚 ③将坩埚充分冷却称量坩埚和剩余固体的质量 ④多次重复步骤②和③至恒重称得坩埚和剩余固体的总质量为35.0克． 4实验时需要重复加热冷却称量操作多次其目的是． 5根据题目中的信息写出NaHCO3完全分解的化学方程式． 6根据题意计算样品中NaHCO3的质量分数．请写出计算过程

Wearelookingforwardtoseeyousoon.

用如图所示的水壶提水时手应提在水壶把手的填A或B下同处把水壶里的水灌到保温瓶中去时手应提在水壶把手的处．出现这样的差别主要是因为力的三要素中力的影响力的．

先化简再求值其中a=-．

投掷出去的铅球在空中能够继续运动这是因为铅球具有在铅球下落的过程中铅球的重力势能逐渐转化为能．

如图所示某人用扁担担起两筐质量为m1m2的货物当他的肩处于O点时扁担水平平衡已知l1＞l2扁担和筐的重力不计． 1在O点时根据杠杆平衡的条件可知m1m2填＞＜或者＝ 2若将两筐的悬挂点向O点移近相同的距离△l则扁担端向下倾斜．填左或者右 3要使扁担恢复水平平衡需再往某侧筐中加入货物其质量为．

计算-22+π-10+·

常熟地处江南水资源总量较丰富下列有关水的说法正确的是

实验室常用电流表的结构如图所示线圈与接线柱相连．当通以图示方向的电流时线圈带动指针向右偏转．下列说法中正确的是

下列命题中错误的是

在水平桌面上竖直放置一个底面积为S的圆柱形容器内装密度为ρ1的液体．将挂在弹簧测力计下体积为V的金属浸没在该液体中液体未溢出．物体静止时弹簧测力计示数为F撤去弹簧测力计球下沉并静止于容器底部此时液体对容器底的压力为容器底对金属球的支持力的n倍．求 1金属球的密度 2圆柱形容器内液体的质量．

如图所示数轴上AB两点对应的实数分别是1和若点A关于点B的对称点为点C则点C所对应的实数为．

2017年5月9日中国科学院发布了113号115号117号及118号四种元素的中名称其中一种元素在元素周期表中的信息如图所示下列有关该元素说法错误的是

铝铁铜三种金属与我们的生活密切相关下列关于铝铁铜的说法错误的是

乙硫醇化学式为C2H6S易挥发有蒜臭味人对该气体极其敏感．下列有关乙硫醇的说法不正确的是

下列常见材料中属于复合材料的是

某工厂排放的废液中含有FeNO32和AgNO3为回收金属Ag设计了如图所示方案． 请回答 1A的名称是A与废液中的成分发生反应的化学方程式为 2过程②中当观察到填实验现象时即可停止加入溶液C 3用实验的方法确定气体D先收集一试管气体

如图一束光线与水平面成35°角射向镜面则入射角是°如果将平面镜绕入射点O逆时针旋转5°则反射角为°．

在测定小灯泡电功率的实验中实验室有以下器材小灯泡额定电压为2.5V电阻约为10Ω电流表0～0.6A0～3A电压表0～3V0～15V开关电压为4V的电源滑动变阻器导线若干．1根据图甲提供的电路用笔画线代替导线将图乙的实物图连接成实验电路．2根据实验中需要测量的物理量．请在图丁方框内画出记录实验数据的表格．3实验过程中闭合开关发现小灯泡不亮电压表没有示数电流表指针有明显的偏转分析电路故障的原因可能是．A．小灯泡断路B．只有小灯泡短路C．只有滑动变阻器短路D．滑动变阻器断路4电路故障排除后某次实验中电流表示数是0.2A电压表示数如图丙所示示数是V此时小灯泡的功率是W．

WouldyoupleasemybotherwhileI'mcooking? A.takeoutof B.takecareof C.takepartin D.takeawayfrom

—IsawAnnagreendressattheschoolmeeting.—Ithinkshelooksbetterred.A.dressed;in B.puton;wear C.wearing;in D.wore;puton

现有一包固体粉末可能含有BaCl2Na2SO4NH4NO3CuNO32BaOH2中的两种或多种．按照图进行实验出现的现象如图中所述假设过程中所有发生的反应都恰好完全反应 1沉淀C的化学式是 2气体B能使湿润的红色石蕊试纸变色 3原固体混合物A中一定不含写化学式 4写出步骤①中一定发生反应的一个化学方程式 5通过上述实验现象还不能确定混合物A中存在的物质是若想进一步判断该物质是否存在可用溶液D再进行实验请你设计实验方案简述操作步骤实验现象及结论

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.作文中共有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删除或修改. 增加在缺词处加一个漏子符号∧并在其下面写出该加的词. 删除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. DearJack Howiseverythinggoingrecently?I'mwritingtotellyousomethingmoreaboutmybirthday.Theotherdayweholdapartytocelebratemy18thbirthday.IreceivedmanypresentsfrommyfriendsandparentsincludingcardsbooksCDsorsoon.Duringthepartywesanganddancedhavinggoodtime.Ithankedmyfriendsforhishelpandcompany.AtthemeantimeIshowedmysincereappreciationtomyparentsforbringingmeup.NowIgrowupthatmeansIshouldshouldermoreresponsibilities.I'lltrymybesttosharemorehouseworkstoreducetheirburden.It'shightimethatIdosomethingtorepaythem. Howdidyoucelebrateyour18thbirthday?I'mlookingforwardtohearfromyousoon. YoursSincerely LiJin

=

用两个相同的温度计并列制成简易干湿温度计其中一个温度计下端的玻璃泡包着湿布使用时水在蒸发这个温度计的读数要比另一个温度计的读数在相同室温下两个读数的差值越大就表明空气中水蒸气含量．

请用笔画线代替导线将图中带拉线开关的电灯正确接入家庭电路中．

巴人广场中心标志性建筑处有高低不同的各种喷泉其中一支高度为1米的喷水管最大高度为3米此时喷水水平距离为米在如图所示的坐标系中这支喷泉的函数关系式是

图甲是探究海波熔化时温度的变化规律的实验装置．1实验中通过水对试管加热而不是直接加热试管目的是．2图乙温度计的示数为℃．3图丙是根据实验数据描绘出的海波温度随时间变化的图象．海波熔化过程对应图线中的段选填AB或BC其熔点为℃．熔化过程中海波吸收热量但温度．4用质量为m1的海波做实验绘制的海波的温度随时间变化的图线如图丁中的a．若用质量为m2m2＞m1的海波做实验得到的图线可能是图丁中的选填bc或d．

先化简再求值其中a=+1b=-1

在化学小组为探究铝铜银三种金属的活动性顺序设计了如图所示实验方案．下列说法不正确的是

Modernsmartphonesarefastbecomingthemust﹣haveitem.Butwhat'sinstoreforthenextgenerationofsmartphones? Tiredofcarryingaroundthatheavywallet?Soonyouwon'tneedto!ThenextgenerationofsmartphoneswillhaveNFCtechnologywhichletsyoupayforthingswithyoursmartphones.Allyoudoisenteryourcreditcardinformationintoyourphone.ThenwhenyouareinashopthatallowsNFCpaymentsyoujustwaveyourphoneoveraspecialinstrumentatthecheckout.Thepurchaseisinstantlychargedtoyourcreditcard. Everseensomeonewearingsomethingandwishedyouknewwheretogetit?SoonitwillbeeasywithPicCommercenewtechnologythatusesimage﹣recognitionsoftware.Here'showitworks.Ifyouseesomethingyoulikesimplytakeaphotoofitwithyoursmartphone.Thenyourphonewillsendtheimagetoaspecialserverwhichwillrespondwithinformationaboutwhereyoucanbuyitandhowmuchitwillcost. Sickofyoursmartphonebatterygoingflat?Withsomanyapplicationsdraining消耗thebatterythelatestphonesneedtobechargedeveryday.Butnextgenerationsmartphoneswillcomewithbuilt﹣inchipsthatcanconnecttoanantenna天线inyourhome.Andaslongasyourphoneiswithinrangeoftheantennayouwillbeabletochargeyoursmartphonewirelesslyevenifitisinyourpocket. Worriedaboutgettingyoursmartphoneswetintherain?AcompanycalledHzohasinventedWaterBlocknewtechnologythatmakesyourphonecompletelywaterproof.Andit'ssoeffectivethatyourphonewillevenworkunderwater. Fedupwithcarryingaheavyphonearound?SoonyouwillbeabletogetaPaperPhone!FlexiblephonesarethefuturesaidscientistRoelVertegaal.Sowhatarethebenefitsofflexiblephones?Wellitmeansthatinsteadofcarryingyourphoneinyourpocketyoucouldwearitwrappedaroundyourwristforexample. Ofcoursethereisjusttheproblemwithsomuchnewsmartphonetechnologyaroundyouwillsoonneedtobuyanewphone! 1Topaywithyoursmartphoneyouneedto. A.gotoabank B.storemoneyinthephone C.haveacreditcard D.buyaspecialinstrument 2Wecanlearnfromthe4thparagraphthatthenextgenerationofsmartphones. A.willhavechipsinsteadofbatteries B.mayconsumelesspower C.needn'tbechargedfrequently D.willbechargedeasily 3WhichfeatureoffuturesmartphonesdoesParagraph6show? A.Theywillbeeasiertocarry. B.Theywillbecheaper. C.Theywillbesmaller. D.Theywillbeeasiertooperate. 4Whatcanbethebesttitleforthetext? A.BasicFunctionsofSmartphones B.TheFutureofSmartphones C.AdvantagesofModernSmartphones D.TheDevelopmentofPhoneTechnology

分析处理图表中的信息是学习化学的一种重要方法如表是NH4Cl和KNO3在不同温度时的溶解度数据 根据上述数据回答下列问题 1从上表可知50℃时NH4Cl的溶解度为g． 2NH4Cl和KNO3的溶解度受温度影响比较大的物质是填化学式． 3欲配制质量分数为10%的KNO3溶液需要的玻璃仪器有烧杯量筒胶头滴管和． 4烧杯中A中是60℃时含有100g水的NH4Cl不饱和溶液经过如图1的变化过程在整个过程中不考虑水分的蒸发则C烧杯中溶液的质量为g． 5某同学欲验证NH4Cl固体溶于水时吸收热量设计如图2实验通过观察到现象得以验证． A．a端液面高于b端液面 B．a端液面低于b端液面．

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. LastFridayourschoolorganizedustoafirestationwhatwehadexpectedseveraldays.Whenwegottherethefire﹣fighterswelcomedusbutledusintoanexhibitionhall.Thereoneofthemdeliversalectureonfirecontroltous.Afterthattheyshowedushowtooperatethefireextinguisherandevengaveourchancestopracticeusingit.NowIdaresayIcanuseitskillful! Onourwayhomewecouldn'thelptotalkingaboutwhatwehadexperienced.Wefeltveryhappyandexcitingbecausewehadgainedsuchmuchknowledgeaboutfirecontrolandknownwhattodoinanemergency. Doyouhaveanythinginterestingtotellme?I'mlookingforwardtoyouremail.

如图所示画出斜面上下滑的物体受到的重力示意图O为作用点

从HCNONaSK七种元素中用适当化学用语填空 1人体中含量最高的元素 2空气中含量最多的气体单质 3金刚石 4不含电子的离子 5纯碱中金属元素的化合价 6可作复合肥的盐 7生成物都是单质的分解反应．

随着物联网技术的发展智能家居已悄然走向前台．下图为智能家居中的安防系统和饮用水净化系统请回答问题 1安防系统 门禁系统智能家居的门禁系统倾向于利用生物识别如指纹锁等．不同的人指纹不同指纹是人的一种性状由决定．烟雾报警图1是烟雾报警器的简化原理图其中电源电压恒定不变R0为定值电阻R为光敏电阻当有烟雾遮挡射向光敏电阻的激光时电路中的电流减小到某一数值时报警器开始报警．则光敏电阻的阻值随光照强度的减弱而选填增大减小或不变此时电压表示数较未报警前选填 增大减小或不变． 2饮用水净化系统 如图2所示在饮用水净化系统中设备①②③的作用分别是．

CityCollegeUnionCompany Secretary/Typist TheUnionisastudent﹣runorganizationwithapermanentstaffof20.Typingspeedatleast60wpm. Theabilitytotakeshorthanddictationandaworkingknowledgeoffillingproceduresareessentialrequirements. Thebasicsalaryforthepositionis﹩18500peryear. EnquirestoR.Barbar387﹣5075. EmuAirline Secretary EmuAirlineisnowofferingapart﹣timepositionforasecretary. Thepositionoffersatleast20hours'workaweekwithaviewtofull﹣timeworkinthefuture.Monthlysalaryisabout﹩1400. Phone899﹣3264foranappointment. WordProcessor Operatorfull﹣time Weneedanoperatortoworkinanofficeassociatedwiththebuildingindustry.Onlyexperiencedoperatorsareexpectedtoapply. Startingsalary﹩17950yearly. ApplyinwritingtothePersonnelOfficerHillMorganPtyLtd38GreenHillRd. SewingMachinistWanted JeansIndustry Weareanexpandingclothingcompanylocatedsouthofthecity.Ourproductsincludejeansskirtsshortsandsoon.Wearelookingforsewingmachineoperators. Thefactoryworksa38﹣hourweekover4﹣5days.Wagesforthisare﹩18050peryear.IfyouareinterestedcomeoverandpickupanapplicationformfromRipperJeans23NorthAveBeaudesert. 1Whatdothesefouradvertisementshaveincommon? A.Eachofthemiscommentedbytheirmanager. B.Theyarelocatedinthesouthofthesamecity. C.Theircompaniesareintroducedindetail. D.Theyallwantpeopleintheproperposition. 2TheapplicantsforthepostofasecretaryinCityCollegeUnionCompanyshouldhavethefollowingqualitiesEXCEPT. A.abilityoforganization. B.knowledgeaboutfillingtheform. C.typingskill. D.writingrapidly. 3TheattractivenessofthepostinEmuAirlineis. A.itspromisingfuture. B.itsfreeflying. C.itsgoodsalary. D.itsniceworkingconditions. 4Ifyouwanttobeasewingmachineoperatoryoumaycontactthiscompanyby. A.visit. B.fax. C.phone. D.email.

现有四种物质①聚乙烯②聚氯乙烯③硝酸钾④活性炭．请用序号填写 1可吸附水中异味的是． 2可用于包装食品的是． 3可用作复合肥的是．

根据如图所示装置回答有关问题 1若实验室用加热氯酸钾和二氧化锰的混合物制取氧气则选取的发生装置为反应的化学方程式． 2若用装置C收集气体气体应从填a或b端导管口通入 3将点燃的蜡烛放入D中连接ADE打开活塞加入液体观察到的现象是E中溶液逐渐变浑浊这一变化的化学方程式为装置A中的物质是．

如图1所示的四种光现象中属于光的反射的是

某课外活动小组的同学在课外实践活动中检测到我市安化县境内某溶洞中的流水中溶有较多量的CaHCO32．下列对该溶洞中的流水的说法不正确的是

如图所示小明采取了三种不同方法往楼上运沙子绳重于摩擦不计下面分析正确的是

Thetigermomwentoutofthebedroomherdaughtercryingsadly.A.left B.leaving C.leave D.toleave

写出下列物质粒子的化学表示式 1五氧化二磷 2硅元素 3碳酸根离子 4三个氧原子

对于某一澄清透明的酸雨样品判断正确的是

计算

IssheaEuropeplayer?

如图所示在暗室里将一个__面镜放在一张白纸上镜面向上用手电筒正对着镜面照射从侧面看去

当入射光线垂直射到镜面时反射光线与入射光线的夹角是度．如果反射光线和入射光线垂直则反射角是度．

如图所示的是小兰家的电能表．此时电能表的示数是kW•h．

asummercampisagreatchancetospend freetimewithyourfriend.A.Join B.Joining C.Tojoin D.Jions

计算

心理学家发现学生对概念的接触能力y与提出概念所用的时间xmin之间满足函数关系y=-0.1x²+2.6x+430≤x≤30．y值越大表示接受能力越强．1x在什么范围内学生的接受能力逐渐增强x在什么范围内逐渐降低2当x=10时学生的接受能力是多少3x为几时学生的接受能力最强

下列除去杂质的方法错误的是

Hepromised  seehisoldfriendduringhisstayinTianjin.

Theoldladynolongerlivedthere.同义句转换Theoldladylivethere .

从微观的角度物质发生热胀冷缩现象的原因是

人体缺钙易引发的病症是

下列说法正确的是

TipsforCookingonaTightSchedule Frommyexperiencetherearethreemainreasonswhypeopledon'tcookmoreoftenabilitymoneyandtime1MoneyisatopicI'llsaveforanotherday.SotodayIwanttogiveyousomewisdomabouthowtomakethemostofthetimeyouspendinthekitchen.Herearethreetipsforgreatcookingonatightschedule 1.Thinkahead.ThemomentswhenIthinkcookingisapainarewhenI'malreadyhungryandthereisnothingreadytoeat.Sothinkaheadofthecomingweek.Whenwillyouhavetimetocook?Doyouhavetherightmaterialsalready?2 2.Makeyourtimeworthit.Whenyoudofindtimetocookamealmakethemostofitandsaveyourselftimelateron.Areyoumakingoneloafofbread?3Ittakesaroundthesameamountoftimetomakemoreofsomething.Sosaveyourselftheeffortforafuturemeal. 3.4Thismaysurpriseyoubutoneofthebesttoolsformakingcookingworthyourtimeisexperimentation.Itgivesyouthechancetohituponnewideasandrecipesthatcanworkwellwithyourappetiteandschedule.Themoreyoulearnandthemoreyoutrythemoreabilityyouhavetotakecontrolofyourfoodandyourschedule. Hopefullythatgivesyouagoodstart.5Anddon'tletabusyschedulediscourageyoufrommakingsomegreatchangesinthewayyoueatandlive! A.Trynewthings. B.Abilityiseasilyimproved. C.Makethreeorfourinstead. D.Understandyourfoodbetter. E.Cookingisaburdenformanypeople. F.Letcookingandlivingsimplybeajoyratherthanaburden. G.Alittletimeplanningaheadcansavealotofworklateron.

请结合图回答问题 1装置图中仪器m的名称是． 2实验室选用AD装置制取O2若加热前装置A中固体为混合物请写出加热时装置A中发生反应的化学方程式． 3若将实验室制取CO2的发生装置由B改为F其优点是．

向某硫酸和硫酸铜的混合溶液中加入某浓度的氢氧化钠溶液产生沉淀的质量与加入氢氧化钠溶液的质量关系如图所示．下列说法正确的是

Forthelovethatshapedmychildhoodandstillcocoons把包围起来metodayIcanneverrepaymygrandfatherormyfatherIfeltthebackofmygrandfather'srough1touchgentlymyjawtodayasheusedtowhenhewastill2whenIwasonlyachildI3abeautifullystampedenvelopefromtheStatesinthemail.Iimmediately4onestampandmyfather'sscrawl潦草的字迹below. 5Iusedaknifetoopentheenvelopeknowingthatoccasionallymy6sentmevaluabletreasurethroughthe7.InsideIfoundanother8.OnitIsawtwoscripts手稿.Thefirstonehadmyfather'sexplanations Inthe40'smygreat﹣grandfatherboughta9.Heuseditinhisofficeatthefamilyrestaurantandwhenhe10mygrandfatherstartedusingthedesk. Whenthefamily11wassoldthedeskwas12tomygrandfather'shouseinNormandy.Latermyfatherdecidedtomovethedesk13andbeginusingit.Whenhedidsohelookedthroughthedrawersofthedeskand14anenvelope. Thesecondscriptboremygrandfather'shandwriting In1972ontheeveofmydeparturefromFrancetoCanadaIhad15mygrandparentsandgivenmybeloved16awildfloweraschildrenwill.Helovingly17itandputitinanenvelopesayingAgiftfrommy‘bouchon'.WillIeverseeheragain? TodayIreceivedproofthatthepeopleinourheartseveniftheirtravelstakethemtoheavencan18touchusinthemostsurprisingways.TodayI19thebackofmygrandfather'sroughfingerstouch20myjawasheusedtowhenIwasonlyachildwhenhewasstillalive 1A.arms B.nails C.legs D.fingers 2A.stubborn B.innocent C.healthy D.alive 3A.fixed B.received C.passed D.gained 4A.recognized B.realized C.evaluated D.claimed 5A.Thankfully B.Gradually C.Carefully D.Hopefully 6A.brother B.father C.mother D.sister 7A.road B.ship C.mail D.traffic 8A.book B.wallet C.bag D.envelope 9A.desk B.chair C.bed D.computer 10A.tookaway B.passedaway C.putaway D.passedby 11A.factory B.business C.restaurant D.element 12A.attached B.supplied C.applied D.moved 13A.again B.far C.fast D.slowly 14A.bought B.found C.invented D.created 15A.controlled B.intended C.visited D.affected 16A.uncle B.aunt C.grandma D.grandfather 17A.made B.eyed C.dried D.pressed 18A.ever B.still C.away D.just 19A.felt B.shook C.thought D.replaced 20A.gently B.calmly C.firmly D.fully