首页
试卷库
试题库
当前位置:
X题卡
>
所有题目
>
题目详情
已知函数f(x)=|ax﹣2|. (1)当a=4时,求不等式f(x)+|4x+2|≥8的解集; (2)若x∈[2,4]时,不等式f(x)+|x﹣3|≤x+3成立,求a的取值范围.
查看本题答案
包含此试题的试卷
高三下学期数学《》真题及答案
点击查看
你可能感兴趣的试题
已知函数fx=-x2+ax-lnx-1Ⅰ当a=3时求函数fx的单调区间Ⅱ函数fx在24上是减函数求实
已知函数fx=ax3+cx+da≠0是R.上的奇函数当x=1时fx取得极值﹣2.求fx的单调区间和极
已知函数fx=x2+2ax+3x∈[-46].1当a=-2时求fx的最值2求实数a的取值范围使y=f
.已知函数fx=ax3﹣3x.Ⅰ若a=4求函数fx的极值Ⅱ若在区间[12]上fx≥4恒成立求正实数a
已知函数fx=3ax-2x2+lnxa为常数 1当a=l时求fx的单调区间 2若函数fx在区间[1
已知函数fx=ax2-a+2x+lnx. 当a=1时求曲线y=fx在点1f1处的切线方程
已知函数fx=ax2﹣4lnx﹣1.Ⅰ当a=1时求fx的单调区间Ⅱ若对一切x∈[2e+1]fx≤4恒
已知函数fx=ax2-2ax+2+ba≠0若fx在区间[23]上有最大值5最小值2.1求ab的值2若
已知函数fx=x2+2ax+3x∈[-46].1当a=-2时求fx的最值2求实数a的取值范围使y=f
已知函数fx=ax3+bx2+cx+da≠0的图象经过原点f′1=0若fx在x=﹣1取得极大值2.1
已知函数fx=x2+4ax+2a+6.1若函数fx的值域为[0+∞求a的值2若函数fx的函数值均为非
已知函数fx=lnx-axa∈R.1求函数fx的单调区间2当a>0时求函数fx在[12]上的最小值.
已知函数fx=x2+4ax+2a+6.1若函数fx的值域为[0+∞求a的值2若函数fx的函数值均为非
已知函数fx=ax3+cx+da≠0是R.上的奇函数当x=1时fx取得极值﹣2.1求fx的单调区间和
已知a∈R函数fx=-x2+axexx∈R.1当a=2时求函数fx的单调区间2若函数fx在-11上单
已知函数fx=2-alnx++2ax.1当a=2时求函数fx的极值2当a
已知函数fx=ax2﹣2ax+2+ba≠0在区间[23]上有最大值5最小值2.1求ab的值2若b<1
设函数fx=ax2+b-8x-a-ab的两个零点分别是-3和2.1求fx2当函数fx的定义域是[01
已知函数fx=x2+2ax+2x∈[-55].1当a=-1时求函数fx的最值2若fx是单调函数求实数
已知函数fx=ax2﹣4lnx﹣1.Ⅰ当a=1时求fx的单调区间Ⅱ若对一切x∈[2e+1]fx≤4恒
热门试题
更多
7.5分Thisactivitywillmeltawaythepoundsbuildyourbodyandleaveyouonanemotionalhigh.Yettheformofexercisethefitnesstrendoftheyeardoesnotrequiregymmembershiporapersonaltrainer.Allyouneedtodoiswalk. Walkingisarefreshingalternativetocomplicatedaerobic氧routinesandoverpricedgymmembershipsayspersonaltrainerLucyKnightauthorofanewbookontheexercise.Itisfreeenjoyableandalreadyapartofeverydaylife.Allyouneedtodoiscorrectyourtechniquewalkfasterandforlongerandyouwillloseweight. Thereismuchevidenceofthebenefitsofwalking.ScientistsattheUniversityofPittsburghrecentlydiscoveredthatoverweightpeoplewhowalkedbriskly快for30to60minutesadaylostweighteveniftheydidn'tchangeanyotherlifestylehabits.AnotherAmericanstudyfoundthatpeoplewhowalkedforatleastfourhoursaweekgainedlessweightthancouchpotatoesastheygotolder.ResearchersattheUniversityofMassachusettsmedicalschoolfoundthatpeoplewhowalkedeverydayhad25percentfewercoldsthanthosewhosatalot.Bestofallwalkingmakesyoufeelgoodaboutyourself.Forpeoplesufferingfromdepressionwalkingthreetofourtimesaweekfor30minuteshasbeenshowntolifttheirmoodsaysKnight. ButhowtowalkyourwaytoweightlossandwellnessHealthexpertsrecommendthatweshouldwalk10000stepsadaytostayhealthy.Actuallyyouwouldprobablyneedtowalkatleast16000stepsadaytoloseweight.Yourworkoutplansdependonyourleveloffitness.Youshouldaimtoprogressbyincreasingyourwalkingtimebyfiveminuteseverytwoweeksandwalkabitfaster.InjustthreemonthstheresultsshouldspeakforthemselvessaysKnight. 1Whatisthelatestfitnesstrendaccordingtothepassage A.Briskwalking. B.Losingweight. C.Workingoutinagym. D.Exercisingwithapersonaltrainer. 2Studiesandresearchesarementionedinthepassagetoshowwalking. A.isgainingincreasingpopularity B.benefitspeopleindifferentaspects C.isanenjoyablewaytoloseweight D.involvesdifferentgroupsofpeople 3Itcanbelearnedfromthelastparagraphthat. A.1600stepsadayisneededforweightlosses B.theeffectofwalkingisnoticeableovertime C.yourfitnessleveldependsonyourhealthexperts D.changingthewalkingtimeeverydayisnecessary
TipsonHowtoSurvivetheExamSeasonWhenitcomestotheexamseasonalotofyoumayfeelstresseddepressedorevenwanttoescape.Herewehavepiecesofadvicetohelpyougetitthrough.1Duringthesemestergoingtolecturesandtakingalotofnotesarethefirststepsinthelearningprocess.Nowattheendoftheweekgatherallthenotesyoutookduringtheweekandrunthroughyournotesquickly2Ifyesgreat.Ifnotyouhavealotoftimelefttounderstandbeforetheexamstakeplace.YoucanaskafriendateacheryoucanlookitupontheInternetorgotoalibrary.Thistakesalittleeffortbuttheresultsaregreat.Switchbetweendifferenttypesofrevision.3Somethingthatreallyhelpsistoplandifferenttypesofactivestudyingwhilerevising.Youcanforexamplestudyusingflashcardsforanhourthenworkonthesummaryforanhourthenhavelunchetc.Makethefactsmorerelatable.Therearemanydifferentwaystodoso.I'mgoingtogiveyoutwoexamplesandthefirstoneistocreatevividimageswhichcanbereallyhelpfulforstudyinghistory.4Thesecondistomakeyourselffamiliarwithnewwordsbylookingforwordsthatlookalikeinotherlanguages.Teachandlearnoutsideoftheclassroom.Inmyexperienceteachingisthemostefficientwayofstudying.Byexplainingthematerialstoyourselfortosomeoneelseyou'llrememberthemalotbetter.5Theideaistositdownandtaketurnsexplainingcertaintopicsofthestudymaterial.Testyourselfwithpastpapers.Attheendofthewholestudyprocessyoushouldprepareyourselftodopastpapersproperly.Timeyourselfdon'tcheatandmarkitasifitwereyourrealexam.Payattentiontothemistakesandrevisethepartyoudidn'tdowellonuntilyoucan'tgetitwronganymore.A.Prepareyourselfinadvance.B.Makesuretobetoughonyourself.C.Evenifyouaremotivatedtostudyeveryonegetsboredafteracoupleofhoursofstudying.D.WhiledoingthisconstantlyaskyourselfDoIunderstandwhatIamreadingE.Askyourparentsorotherfamilymemberstoactasstudentsandlistentoyourexplanation.F.Trytoimaginehowtheeventstookplaceandthisallowsyoutoremembercertaindetailsmoreaccurately.G.Lookforastudybuddyorsmallstudygroupanddiscusseverythingyouhavestudiedbeforetheexam.
如图以∠AOB的顶点O为圆心适当长为半径画弧交OA于点C交OB于点D.再分别以点CD为圆心大于CD的长为半径画弧两弧在∠AOB内部交于点E作射线OE连接CD.则下列说法错误的是
在做“探究影响滑动摩擦力大小的因素”时将木块A放置于水平木板B上加载一个砝码把弹簧测力计系在A上如图所示.当向左拉动B时弹簧测力计指针稳定.下列讨论中错误的是
Thedesiretobenoticedbypeers同龄人isanaturaltendency.Yourstyle﹣﹣thewayyoudressupthewayyoucarryyourselfthetrendsyoufollow﹣﹣playsakeyroleinhelpingyoustandoutfromtheothers.1Thefollowingtipscanhelpyou.1.Beyourself.Whybeasecond﹣rateversionofanybodyelsewhenyoucanbethefirst﹣rateversionofyourself.Nothingwillhelpyoustandoutofthecrowdmorethanyourownfeaturesbecausetherecanbeonlyoneyou.Everyonehastheirownbelieftheirownwayofthinkingtheirownexperiencesthatshapetheirstyles.Howeverself﹣doubtandfearofdisapprovaldrivemanytoabandontheirownwaysandfollowwhateveryoneelseisdoing.22.Keepanopenmind.Open﹣mindednesshelpsyouseethingsfromadifferentperspectiveunderstandothersfindopportunitiesandlearnfromothers.3Thereareseveralstylesthatyoushouldexploreanddeterminewhichsuitsyourownpersonality.Nobodyknowswhatfashionyouareenthusiasticabout.Butyoushouldbeclearlyawareofyourowntruefeelingsaboutit.3.Keepupwiththerecenttrends.Fashionisalwayschanging.4Associetychangessodoesfashion.Changingtrendsreflectthechangesinpeople'staste.Similarlyyoursensesoffashionchangesasyougainmoreexperiencesinlife.Keepingtrackofthelatestfashionwillhelpyouredefineyourstyle.4.Wearyourconfidence.Yourattitudetowardsdressingcanmakeasignificantdifferenceonhowyoulook.Youcanwearaverybeautifuldressbutifyoucan'tcarryitwithconfidenceitwillnotlookgoodonyou.5Don'twearanuncomfortabledressjustbecauseeveryoneoryourfriendiswearingit.Rememberit'sokaytohaveyourownstyleaslongasyouareconfidentwithit.A.Alsoittellsalotaboutyourpersonality.B.Whatworkedyesterdaymaynotworktoday.C.Copyingotherswillmakeyoujustanotherfaceinacrowd.D.Havinganopenmindcanbeveryhelpfulindefiningyourstyle.E.OntheotherhandevenanaveragedresslooksgreatonpeoplewhowearitconfidentlyF.Itisnotabsolutelynecessarytofolloweverynewtrendandyoucanenjoytheonesyoulike.G.Simplyfollowingthefashiontrendsorwearingexpensiveclotheswillnothelpyougetadistinctstyle.
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. NowadaysthecomputertechnologydevelopsveryfastthattheInternethasbecomemoreandmorepopular.Somestudentsregardeditasagreathelper.BecausetherehasalotofinformationonlinesotheycansurftheInternetforanyinformationtheyneedinashorttimewithoutworkinghardinthelibrary.ThisisalsoveryconvenienttotalkwithothersbyusingtheInternet.Moreoverotherstudentsthinkthatthereissomeinformationonlinethatisnotgoodforstudents.Inadditionspendtoomuchtimeplayinggameswillnotonlyhaveabadeffectontheirstudiesbutalsodoharmstohealth.ThereforeweshouldmakeproperlyuseoftheInternet.It'sofgreatimportanceseparategoodplantsfromwildweeds.
如图已知在等边三角形ABC中D是AC的中点E为BC延长线上一点且CE=CDDM⊥BC垂足为M求证DM垂直平分BE
An80﹣year﹣oldmanwassittingonthesofainhishousealongwithhis45﹣year﹣oldhighlyeducatedson.Suddenlyacrow乌鸦perchedonthetreeneartheirwindow. ThefatheraskedhissonWhatisthisThesonrepliedItisacrow. AfterafewminutesthefatheraskedhissonthesecondtimeWhatisthisThesonsaidFatherIhavejustnowtoldyouIt'sacrow'. Afteralittlewhiletheoldfatheragainaskedhissonthe3rdtimeWhatisthis Atthistimesomeexpressionofirritation恼怒wasfeltintheson'stonewhenhesaidtohisfatherunwillingly.It'sacrowacrow.AlittlewhileafterthefatheragainaskedhissonthefourthtimeWhatisthis ThistimethesonshoutedathisfatherWhydoyoukeepaskingmethesamequestionagainandagainalthoughIhavetoldyousomanytimes‘ITISACROW'.Areyounotabletounderstandthis Alittlelaterthefatherwenttohisroomandcamebackwithanoldtattered发皱的diarywhichhehadmaintainedsincehissonwasborn. Onopeningapageheaskedhissontoreadthatpage. Whenthesonreaditthefollowingwordswerewritteninthediary Todaymylittlesonagedthreewassittingwithmeonthesofawhenacrowwassittingonthewindow.Mysonaskedme23timeswhatitwasandIrepliedtohimall23timesthatitwasacrow.Ihuggedhimlovinglyeachtimeheaskedmethesamequestion.IdidnotatallfeelirritatedbutIratherfeltaffectionformyinnocentson. 注意 1.所续写短文的词数应为150左右 2.应使用5个以上短文中标有下划线的词语 3.续写部分分为两段每段开头语已为你写好 4.续写完成后请用下划线标出你所使用的关键词语 Paragraph1Afterreadingthediary. Paragraph2Feelingashamedthesongotdownonhiskneesbeforehisfather..
AfewyearsafterValeriaLuisellibeganwritingLostChildrenArchiveshebrokeofftowritesomethingmoreurgent.FormonthsLuiselliwhowasborninMexicoandlivesintheUnitedStateshadbeenvolunteeringasaninterpreterforundocumentedchildmigrants移民appealingforshelterintheUS.Itwasheartbreakingandhardandnoneofthoseshehelpedhasintheyearssincebeengivenpermissiontostay.Luiselli'swritingpausedandinafevershewroteTellMeHowItEndsanon﹣fictionaccountoftheterriblejourneyofthesechildren.Icouldn'tthinkorwriteaboutanythingelse.ThatbookwastheevidenceofwhatIwasseeing. WhatshewasseeingwasthisMexicanchildrenwhohadenteredthecountryunaccompaniedaboardLaBestia﹣thebeast﹣anetworkoftrainsontheroofsofwhichhalfamillionCentralAmericansrideannually.Itisterrificallydangerous.Thosewhodon'tfallontothetracksriskdeathfromexposureoverhangingbranchesorviolencefromrobbersthievesandpolicewhoattackpeopleonboard.Butofcoursechildrendowhattheirstomachstellthemtodo.Theychaseafterlifeevenifthatchasemightendupkillingthem.IfandwhentheyfinallyreachtheUStheyfallintothehandsofimmigrationofficersknowntoshoutSpeakEnglish!Nowyou'reinAmerica!andanewnightmarebegins. Theactofbearingwitnesswouldbecomethedrivingforcebehindthenoveltowhichshereturned.LostChildrenArchivelonglistedfortheWomen'sprizeforfictionthisweek.ValeriaLuisellialsofoundthevalueoffictionitself.SometimesalittlelightcanmakeyouawareofthedarkunknownspacethatsurroundsitwritesLuiselliinthenovel.Andthatrecognitionandtoleratingdarknessismorevaluablethanallthefactualknowledgethatmayeveraccumulate. 1ValeriaLuisellipausedhiswritingLostChildrenArchivemainlybecause. A.Shehadtoworkfull﹣timeasavolunteertohelpthepoor. B.Shedecidedtocollectsomeevidenceforhernewnovel. C.Shecouldn'tsupportherfamilybywritinginAmerica. D.ShedesiredtowriteabouttheMexicanchildmigrants. 2WhichofthefollowingdangersisNOTincludedduringthejourney A.Fallsonthetracks B.Attackfrompolice C.Violencefromdrinkers D.Deathfromexposure 3Whatcanbeinferredfromthepassage A.ChildrenmayhavebrightfutureinAmerican. B.ValeriaLuisellivaluedthefactualknowledgemost. C.ManychildrenmightsufferfromhungerinMexico. D.ValeriaLuiselliwouldfinallyabandonherwriting. 4WhichofthefollowingwordcanbestdescribeValeriaLuiselli A.sympathetic B.humorous C.creative D.optimistic
Indoorplantsaddcolorandwarmthtothehome.Manyhouseplants1beeasytogrowbuttheymustbegivenappropriatecare. Theveryfirstthingtoconsiderwhen2selectahouseplantiswhereyouwanttoputit.Thenmatchthespaceandlightingwiththeplant'srequirements.Doyouhaveabigspotbya3sunwindoworasmallspacewithlittlelightNextask4youwhetheryouarelookingforaplantwithbeautifulgreenleaves5afloweringplant.Somefloweringhouseplantsareseasonalwhileotherswillbloomyearafteryear. Wateringproperlyisoneof6mostimportantpartsofindoorplantcare.Roomtemperaturetapwatershouldbefineformostindoorplantsbutremembernot7watertoomuchatatimeotherwisetheywill8certaingetdrowned. Someplantsgrowwellinwarmhumidenvironmentswhileotherspreferhotdryclimates.Ofcourseyourhomecan'tbeeverythingtoeveryplantbutifyoucantakeplantneedsinto9consideryoucanmakesurethatyourplantsareliving10theiridealenvironment.
如表是小明测一滑轮组机械效率时收集的有关数据. 1请在图中画出实验中滑轮组的绕绳方法 2在实验过程中应沿竖直方向拉弹簧测力计 3表格中空缺的数据为 4分析表中数据可知用同一滑轮组提升不同重物至同一高度提升的物重增加时所做的额外功其中除克服动滑轮重所做的额外功外其它额外功将前两空选填“变大”“变小”或“不变”.造成额外功大小变化的原因是.
为便于测量或观察现象实验中我们经常会对实验进行优化改进.下列采取的措施不合理的是
在探究“比较不同物质吸热的情况”的实验中实验装置如图所示. 1本实验中应量取质量的甲乙两种液体分别倒入相同的烧杯中用相同的电加热器加热通过选填“升高的温度”或“加热的时间”来反映物质吸热的多少. 2分析实验数据当甲升高8℃乙升高16℃时物质的吸热能力强. 3进一步分析数据可知c甲c乙. 4若要选择一种液体作为汽车的冷却液应选择液体.
运用乘法公式简便计算19992-1998×2002
如图所示为生活中常用的热水瓶注入一定量的热水后立即盖上软木塞软木塞常会跳起来.在软木塞跳起来的过程中热水瓶内温度选填“升高”“不变”或“降低”.汽油机中的冲程与这一现象的能量转化相同.
小明学习了电学知识以后想在家里安装一盏照明灯和一个三孔插座他设计的电路如图所示图中虚线框A和B内分别接入开关或灯泡则虚线框A内应接图中三孔插座的插孔选填ab或c应与地线相连.
图示电路中电源为恒流源能始终提供大小恒定的电流R0为定值电阻移动滑动变阻器R的滑片则下列表示电压表示数U电路总功率P随电流表示数I变化的关系图线中可能正确的是
如图所示杠杆OBA处于平衡状态请分别画出力F1的力臂L1和力F2的力臂L2.
已知a+b=3ab=2则a2+b2=
计算5x+42-3x-3x+2
如图△ABC绕着点C顺时针旋转37°得到△A1B1C若A1B1⊥AC则∠A的度数是
观察下列各式x-1x+1=x2-1x-1x2+x+1=x3-1x-1x3+x2+x+1=x4-11填空x5-1=2根据规律可得x-1xn-1++x+1=其中n为正整数3计算3-1350+349+348++32+3+14计算-21999+-21998+-21997++-23+-22+-2+1.
WhenIwas16IreadamagazinearticleaboutamuseumcalledtheMcKayoncethehomeofawatercoloristnamedMarianMcKay.Shehadrequestedthecommunitytoturnitintoamuseumuponherdeath.OnasunnySaturdaySallyandIdroveovertothemuseum.SheaskedDoyouhavetheaddressNobutI'llrecognizeittherewasapictureinthemagazine. Ohstop.Thereitis! Themuseumwasfree.Weenteredexcited.Agroupofpeoplesittinginthehallstoppedtalkingandstaredatus. MayIhelpyouamanasked.NoIsaid.We'refine.Tourguidesgotonmynerves.Whatiftheytalkedalongtimeaboutapaintingyouweren'tthatinterestedinSallyhadgoneupstairs.Thepeopleinthehallseemedverynosy爱窥探的keepingtheireyesonmewithcuriosity.WhatwastheirproblemIsawsomenicesculpturesinoneroom.SuddenlyIsensedamanstandingbehindme.Wheredoyouthinkyouareheasked.Iturnedsharply.TheMckayArtMuseum!Hesmiledshakinghishead.SorrytheMckayisonNewBraunfelsStreet.What'sthisplaceIaskedstillconfused.Wellit'sourhome.Myheartjolted震颤.IracedtothestaircaseandcalledoutSally!Comedownimmediately! There'ssomereallygoodstuffupthere.Shesteppeddownlookingconfused.IpushedhertowardthefrontdoorwavingatthefamilysayingSorrypleaseforgiveusyouhaveareallyniceplace.OutsidewhenItoldSallywhathappenedshecoveredhermouthlaughing.Shecouldn'tbelievehowlongtheyletuslookaroundwithoutsayinganything. TherealMcKaywassplendidbutwefeltnervousthewholetimewewerethere.VanGoghPicasso.Thistimewestayedtogetherincaseanythingelseunusualhappened. Thirtyyearslaterawomanapproachedmeinapublicplace.ExcusemedidyoueverenteraresidencelongagothinkingitwastheMcKayMuseum Yes.ButhowdoyouknowWenevertoldanyone. Thatwasmyhome.Iwasateenagersittinginthehall.BeforeyoucameoverIneverrealizedwhatabeautifulplaceIlivedin.Ineverfeltluckybefore.Youthoughtitwasamuseum.Myfeelingsaboutmyhomechangedafterthat.I'vealwayswantedtothankyou. 1Howdidtheauthorfeelaboutbeingstaredatbythepeopleinthehall A.Concerned. B.Frightened. C.Puzzled. D.Delighted. 2Whydidtheauthorrefusethehelpfromthemaninthehouse A.Shedislikedpeoplewhowerenosy. B.Shefeltnervouswhentalkingtostrangers. C.Sheknewmoreaboutartthantheman. D.Shemistookhimforatourguide. 3WhydidtheauthordescribetherealMcKaymuseuminjustafewwords A.Therealmuseumlackedenoughartworktointeresther. B.Shewastooupsettospendmuchtimeattherealmuseum. C.TheMcKaywasdisappointingcomparedwiththehouse. D.Theeventhappeninginthehousewasmoresignificant. 4Whatcouldwelearnfromthelastparagraph A.Peopleshouldhavegoodtastetoenjoylife. B.Peopleshouldspendmoretimewiththeirfamily. C.Peopletendtobeblindtothebeautyaroundthem. D.Peopletendtoeducateteenagersatamuseum.
图甲是建造大桥时所用的起吊装置示意图使用电动机和滑轮组图中未画出将实心长方体A从江底竖直方向匀速吊起图乙是钢缆绳对A的拉力F1随时间t变化的图象.A完全离开水面后电动机对绳的拉力F大小为6.25×103N滑轮组的机械效率为80%已知A的重力为2×104NA上升的速度始终为0.1m/s.不计钢缆绳与滑轮间的摩擦及绳重不考虑风浪水流等因素的影响g取10N/kg求 1长方体A未露出水面时受到的浮力 2长方体A的密度 3长方体A完全离开水面后在上升过程中F的功率.
阅读下面短文根据其内容写一篇60词左右的内容概要. NowadaysanincreasingnumberofyoungChinesespendmoneybecausetheyarelazy.AccordingtoareportissuedinDecemberbyChina'se﹣commerceplatformTaobaoonChina'slazyeconomyChinesepeoplespent16billionyuanonproductsandservicesonlinein2018.Thepost﹣1995generationwasthelaziestasitsconsumptionincreasedby82percentcomparedwiththatin2017. Theso﹣calledlazyeconomyreferstoanewtypeofconsumptionofproductsandserviceswhicharedesignedtosavetimeandlabor.Accordingtothereportmanypeopleofthepost﹣1995generationbuyhigh﹣techelectronicdevicessuchasfloormoppingrobotsandautomaticwindowcleanerswhichsavethetroubleofdoinghouseholdchores.Meanwhiletake﹣outfooddeliveryservicesarealsopopularamongpeoplebomafter1995. Youngpeoplearewillingtospendmoneyonsuchproductsbecausetheywanttoenjoyhard﹣earnedleisuretimeafterabusyandstressfuldayatworkorschoolreportedGlobalTimes.Becausetheyneedtofocusontheirstudiesorjobstheseso﹣calledlazypeopletendtousetheirleisuretimemoreefficiently.ForexampleWeiDuoa21﹣year﹣oldcollegestudentisafrequentuseroftake﹣outfooddeliveryservices.Ioncehadabirthdaycakedeliveredtomyfriendwholivesfarfrommyhome.Itcostme50yuanbutitsavedmealmosthalfadaythatwouldhavebeenneededtodeliveritmyself.Myfriendwasalsohappybecauseshegottocatthecakeinstantly''WeitoldtheGlobalTimes. Whilethelazyeconomymightbeconvenientforyoungpeopleitmightalsocreateproblems.The‘lazyeconomy'oncampusisexpressedinthingslikepeoplebuyingfoodorotherthingswithoutleavingthedormitory.Asaresulttheystayintheirdormitoriesalldaylongplayingoncomputersandsmartphones.AccordingtoJinanDailythissituationcouldleadtoyoungpeoplebecominglesssociableandevendevelopingproblemsofcommunicatingwithothers.Youngpeopleshouldbealert努觉的toit.
如图所示将苹果和梨子放入水中后苹果漂浮梨子沉底.若苹果的质量体积及受到的浮力为m1V1和F1梨子的质量体积及受到的浮力为m2V2和F2现有以下判断正确的是 1若m1>m2则F1一定小于F2 2若m1=m2则F1一定大于F2 3若V1=V2则F1一定小于F2 4若V1>V2则F1一定大于F2.
运用乘法公式简便计算7002-1400×695+6952
如图甲所示电路中电源电压可调灯L1L2的额定电压均为6VL1L2的I﹣U图象如图乙所示闭合开关S逐步调大电源电压至电路允许的最大值此时
如图所示是某餐厅出现的一款餐饮机器人可以为客人送上凉菜主食等. 1送餐时机器人在1min内沿直线匀速移动了15m此过程中机器人运动的速度是多少m/s 2机器人送餐时总质量为42kg它与水平地面接触的总面积为100cm2则它对地面的压强是多少g取10N/kg
热门题库
更多
高三上学期数学
高一下学期英语
教案备课库
高一上学期生物
高一下学期生物
高二上学期数学
高二上学期物理
高二上学期英语
高二上学期生物
高二下学期数学
高二上学期化学
高二下学期物理
高三下学期物理
高三上学期物理
高三上学期生物
高三上学期化学