首页
试卷库
试题库
当前位置：
X题卡
>
所有题目
>
题目详情
①用游标为10分度（测量值可准确到0.1mm）的卡尺测量小球的直径，测量的示数如图甲所示，读出小球直径d的值为 mm． ②用螺旋测微器测金属丝的直径测量的示数如图乙所示，读出测金属丝的直径d...
查看本题答案
包含此试题的试卷
高三下学期物理《》真题及答案
点击查看
你可能感兴趣的试题
甲乙丙三位同学在使用不同的游标卡尺测量同一个物体的长度时测量的结果分别如下甲同学使用游标为50分度的
用游标为50分度的卡尺测量值可精确到0.02mm测定某圆筒的内径时卡尺上的示数如图甲所示可读出圆筒的
用游标为50分度的卡尺测量值可准确到0.02mm测定某圆筒的内径时卡尺上的示数如图可读出圆筒的内径为
4分甲乙丙丁四位同学在使用不同精度的游标卡尺和螺旋测微器测量同一个物体的长度时分别测量的结果如下甲同
甲乙丙三位同学使用不同的游标卡尺测量某圆筒的直径时测量结量分别如下甲同学使用游标为10分度的卡尺读数
甲乙丙三位同学在使用不同的游标卡尺测量同一物体的长度时测量的结果分别如下甲同学使用游标为10分度的卡
有一根横截面为正方形的薄壁管如图5所示现用游标为50分度测量值可准确到0.02mm的游标卡尺测量其外
有一种游标卡尺在游标尺上有20个小等分刻度它们的总长度为19mm它的每一分度与主尺的最小分度1mm相
游标为20分度测量值可准确到0.05mm的卡尺示数如图1所示两测角间狭缝的宽度为mm.用激光照射该狭
用游标为50分度的卡尺测量一工件的直径测量结果如图所示此工件的直径为mm.
在用单摆测定重力加速度的实验中测出了单摆在摆角小于5°时完成n次全振动的时间为t用毫米刻度尺测得摆线
用游标为20分度测量值可准确到0.05mm的游标尺测定一个圆筒的深度时卡尺上部分刻度的示数如图甲所示
用游标为50分度的卡尺测量值可准确到0.02mm测定某圆筒的内径时卡尺上的示数如图可读出圆筒的内径为
1通常游标卡尺的刻度有10分度20分度50分度三种规格其中50分度的总长是_______mm准确度是
有一根横截面为正方形的薄壁管如图1所示现用游标为20分度测量值可准确到0.05mm的游标卡尺测量其外
6分用游标为20分度测量值可准确到0.05mm的游标卡尺测量一小球的直径测量结果如图甲所示.如用螺旋
泥沙粒径测量可选分度值0.1mm的游标卡尺这种精度的游标卡尺尺身上的最小分度是1mm游标尺上有10个
0.1
0.2
0.3
0.4
用游标为20分度的游标卡尺测量某一工件长度示数如图甲所示用螺旋测微器测其直径d示数如图乙所示则此工件
2016年·北京市西城一模用游标为10分度测量值可准确到0.1mm的卡尺测量小球的直径测量的示数如图
4分用游标为20分度测量值可准确到0.05mm的游标卡尺测量一小球的直径测量结果如图甲所示.如用螺旋
热门试题
更多
ThemomentIsteppedoffmyplaneafterawriter'sconferencemyyoungestsonJeremygreetedmeandcriedPosterpaperMama!Ineedposterpaper.We'rehavinga41atschool. BeingahousewifeandwriterIfeltlikenomatterhowhardItriedIcouldn'tkeepupwiththeneedsofmy42.BackathomeJeremykeptremindingmeoftheposterpaperbutIjustcouldn't43aminuteforit.Graduallythoughhebegantospeakmore44almostasthoughheweretalkingtohimself.Maybehe'lljust45itIthoughthopefully.SoIputJeremy'srequestatthe46ofmylonglistofthingstodo. MythirddayhomeImanagedtotakefifteenminutestotypeanarticlewhenasmall47fellacrossmypaper.IknewwhoitwouldbebeforeI48.Jeremystoodquietlywatchingme.Oh.Lordpleasedon'tlethimsayitagain.IknewwhathewantedbutIneededto49Ismiled50atJeremyandkepttyping.He51forafewmoreminutesthenturnedandwalkedaway.Ialmostdidn'thearhis52.Competitionisovertomorrowanyway.ThesmallfigurewalkingoutofmyroomasilentvoicespokeurgentlytomyheartGethimthatpaper﹣now! Let'sgotogetthepaperJeremy.Hestopped53andlookedatmein54You'regoingtothestorejustforme?I55.Suddenlyalookof56shotacrosshisfaceerasingthedisbelief.Idon'tthinkI'llever57thatmoment.Laterthatdayheworkedsilentlyonthe58allafternoon.Andafewweekslateralargeyellowenvelopecame.InsideitwastheCertificateofAward.So59wasIthatIdidn'tturnedawayfromhis60togethimsomeposterpaper. 41.A.race B.class C.ceremony D.competition 42.A.colleagues B.family C.neighbors D.relatives 43.A.spare B.wait C.spend D.lose 44.A.slowly B.softly C.confidently D.meanly 45.A.want B.buy C.forget D.get 46.A.bottom B.top C.beginning D.corner 47.A.letter B.foot C.image D.shadow 48.A.wokeup B.stoodup C.gotup D.lookedup 49.A.rest B.type C.learn D.exercise 50.A.widely B.happily C.weakly D.politely 51.A.watched B.searched C.hesitated D.complained 52.A.comment B.footsteps C.warning D.advice 53.A.fellover B.satdown C.turnedaround D.walkedaway 54.A.peace B.relief C.astonishment D.silence 55.A.doubted B.argued C.apologized D.nodded 56.A.surprise B.sadness C.disappointment D.excitement 57.A.enjoy B.remember C.forget D.value 58.A.story B.question C.poster D.composition 59.A.grateful B.generous C.forgetful D.selfless 60.A.opinion B.request C.promise D.gift
求下列函数的最大值或最小值．y=1﹣2x﹣x2．
求下列函数的最大值或最小值．y=x²-3x+4
SomethingIenjoydoingmostinmyleisuretimeisgoingtothecinematowatchagreatfilm.It'stwohoursofrelaxationandescapismfromreallife.ButwhenIkickbackinmyseattoenjoythefilmandtuckintomyboxofpopcornI'moftenirritatedbyseeingsomeonenexttometextingontheirmobilephoneorworsestilltalkingtosomeone. It'snosurprisethataproposalbyaUScinemachaintoletpeopleusetheirphonesduringsomefilmscreeningswasmetwithsuchangerthatthecompanyhadtowithdrawtheidea.Peoplesaiditwas'theworstideaever'!Surelygoingtowatchthelatestfilmisjustthat﹣watchingnotmulti﹣screening.Andifyou'reoutwithafrienditseemsveryantisocialorjustrude.Icertainlygetdistractedbytheclick﹣clickonsomeone'smobilekeyboardastheytextandtheglowofthebrightsmallphonescreen﹣whyaren'ttheyconcentratingonthebigscreen?! ButwiththeavailabilityofstreamingfilmsathomeandcheapDVDscinemasarestrugglingtokeeptheircustomers.Someplacesnowoffercomfortableseatswithcomplimentarysnacksanddrinkssomaybetryingtoattractayoungeraudiencebyallowingtheuseofmobilephonesisthewayforward?Asurveyin2012foundthatamajorityof18﹣to﹣34﹣year﹣oldsbelievedusingsocialmediawhilewatchingamoviewouldaddtotheirexperience. Howevernoteveryyoungpersonwantstomulti﹣taskatthemovies.Manyofusstillgetannoyedbythetheatrestaffwhoappearnottodoanythingaboutit.OfcoursewecouldasktheoffenderstoturntheirphonesoffbutasAdamAronheadofAMCEntertainmentsaidinVarietymagazine6/whenyoutella22﹣year﹣oldtoturnoffthephonedon'truinthemovietheyhear'pleasecutoffyourleftarmabovetheelbow'.ClearlythisisnotwhatIwouldliketoseebutifyouwanttouseyourmobilephoneinthecinemathatI'matpleasedon'tsitnexttome!Whatdoyouthinkistherightthingtodo? 28.TheunderlinewordirritatedinParagraph1means. A.terrified B.depressed C.annoyed D.embarrassed 29.WhichofthefollowingisTrueoftheUScinemachain'soriginaladvice? A.Theadvicewascarriedoutsmoothly. B.Theypermittedpeopletousethephone. C.Theadvicewasverypopularwithpeople. D.Theyprohibitedpeopletousethephone. 30.WhatcanweinferfromParagraph3? A.Youngpeopleusetheirsocialmediafrequently. B.Thecinemaneedn'tworryabouttheircustomers. C.PeopleprefertowatchfilmsandDVDathome. D.Sendingmessagesisthebestexperienceforyoungpeople. 31.Whatistheauthor'sattitudetowardsmulti﹣taskatthemovies? A.Sympathy.B.Encouragement.C.Enthusiasm.D.Disapproval.
给试管里的固体药品加热时错误的是
Itiscommonthatwemayhearmanystoriesofindividualswho'veadoptedazero﹣wastelifestylebutit'snotoftenthatwecomeacrossanentirecommunitythatistryingtobecomewaste﹣free.TheresidentsofKamikatsuJapantakerecyclingsoseriouslythattheyactuallyhopetobecomethenation'sfirstzero﹣wastecommunityby2020. Kamikatsuhasnogarbagetrucks﹣soresidentsneedtocompost制成堆肥theirkitchenwasteathome.Theyalsohavetowashandsorttherestoftheirwasteinto34differentcategoriesandbringittotherecyclingcenterthemselveswhereworkersmakesurethatthewastegoesintothecorrectbins.Itapparentlytooksometimefortheresidentstogetusedtothisrulebuttheyeventuallymanagedtoadapttothechangesandarenowseeingthemasnormal.TheJapanesetownhasturnedrecyclingintoastreamlinedprocess﹣thereareseparatebinsfordifferenttypesofpaperproductsandevenplasticbottlesandtheircapsgointodifferentbins.Thelabelsoneachbinshowtherecyclingprocessforthatspecificitemsotheresidentsknowexactlywhathappenstotheirwaste. ReuseishighlyencouragedinKamikatsu﹣theyhavealocalkuru﹣kurushopwhereresidentscanexchangeuseditemswithnewthingsatnoextracost.Andthekuru﹣kurufactoryemployswomentomakebagsclothesanddollsoutoftheseitems.Businessesarealsoencouragedtoparticipateinwastemanagement﹣thetownhasazero﹣wastebreweryhousedinabuildingconstructedofreusedmaterials. AlltherecyclingfacilitiesinKamikatsuaremanagedbyaZeroWasteAcademywhichalsoregularlyhostsgroupsoflocalschoolchildrenandforeignvisitorseducatingthemonthebenefitsofazerowastelifestyle. 33.AccordingtoParagraph2wecanlearn. A.theJapanesetownhasmaderecyclingaroutine B.therearepart﹣timeworkerstosortoutthewaste C.thelabelsshowthecitizenshowtocomposttheirwaste D.thekitchenwastemustbesortedoutintodifferentkinds 34.WhatdoestheZeroWasteAcademydo? A.ithelpsthecitizenstoexchangeuseditemswithnewthingsatnoextracost. B.itemployswomentomakebagsclothesanddollsoutoftheseitems. C.iteducatespeopletoliveinazerowastelifestyle. D.itconstructsbuildingswithreusedmaterials. 35.Whatdoesthepassagemainlytalkabout? A.Thebenefitsofazerowastelifestyle. B.Theeffectivemanagementofwasterecycling. C.Howcanweusetherecycleditems? D.HowdoesKamikatsubecomeazero﹣wastecommunity?
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短文.短文中共有10处错误每句中最多有两处.错误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∧并在此符号下面写出该加的词. 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. Inthepastmyhometownwasverysmall.Peopletherelivedpoorlifeandthehousesareveryoldandshabbysomeofwhichwereevenshakinginthewind.Astothetrafficitwastooinconvenientthatalmostnotouristscame. Besidesmanychangeshavebeentakenplaceinmyhometownbynow.Lifehasbecomebetter.Thehouseshavebecomelargerandbrightandmorepeoplehavegottheirowncar.Everywhereisdecoratedofgreentreesandbeautifulflowers.What'smorethousandsoftouristsfromallovertheworldcomehereeveryyearitisreallysplendid.Ibelievemyhometownwillbecomemoreandmoredevelopingandbeautiful.AndIamproudofit.
根据实验规范下列实验操作正确的是
求下列函数的最大值或最小值y=-x²-4x+1
假如你是李华你的美国朋友Tom将于7月来华学习汉语让你帮他在学校附近租一套合适的公寓.请根据下图和文字提示给他回一封英文电子邮件. 要点包括:1.表示欢迎; 2.公寓概况; 3.期盼回复. 注意:1.词数100左右; 2.可适当增加细节使行文连贯; 3.开头和结尾已给出不计入总词数. DearTom Yours LiHua.
Howmuchempathy共鸣doyoufeeltowardsotherpeople?Ifyousawsomeonefallofftheirbikeintrafficwouldyoustopandhelp﹣orjustwalkaway?Manypeoplewouldgiveintocoldnessgoabouttheirbusinessandjustdonothing.Soitwasabigsurprisewhenabout100bystandersgottogetherrecentlytomoveabusineastLondontohelpacyclisttrappedunderit.Avideooftheincidentwentviralonsocialmedia. AccordingtoZohebadriverwhostoppedhiscartotakepartintherescueaboutfivepeoplegatheredtomovethebus.Hesays:Therewasnochancewecoulddoititwasmoreaninvitationforotherpeopletohelpreally. Theinitiative主动能力paidoff.Dinersfromnearbyrestaurantsjoinedin.Therewasn'tmuchcoordinationbutitdidn'ttakelongtodevelopacollectiveunderstandingofwhattheobjectivewas. Spontaneous自发的cooperationamongstrangersdoesn'thappenoften.Peopleinacrowdarenotsurewhattodo﹣theydon'thaveaplan.It'soneofthereasonsbystandersoftendonothingaccordingtoDrMarkLevineprofessorofsocialpsychologyatExeterUniversityinBritain.Thepresenceofotherscanpreventyoufromhelpinghesays. ThekeytopositivegroupbehaviourLevineexplainsisbuildingasenseofsharedidentity.Actionhastobedecidedquickly.Levinesays.Thelongeryouleaveittheharderitistomakeadecision.Ifyoudon'timmediatelyactthenyoukindofthink'WellactuallyIprobablycouldn'thavedoneanythinganyway'. ButthepeoplewhotooktheinitiativelikeZobebmightmakeadifference.Thecyclistendedupinhospitalandtheimagesofthecollectiveeffortmightinspireotherstomoreactsofunity. 24.Whydidtheauthorsayitwasabigsurprisewhentherescuewasmade? A.Somanypeoplegaveahand. B.Manybystandersdidnothing. C.Itspreadonsocialmedia. D.Itdidn'tcatchpeople'sattention. 25.WhichofthefollowingbestdescribesthedriverZohebaccordingtothetext? A.Generous. B.Kind﹣hearted. C.Optimistic. D.Easy﹣going. 26.WhydopeoplegiveintocoldnesswhentheyshouldbehelpingaccordingtoLevine? A.Theydon'tknowhowtogivefirstaid. B.Nobodywantstobethefirsttoofferhelp. C.Strangersseldomcooperatewitheachother. D.Theyareforbiddenfromhelping. 27.Whatcanwelearnfromthetext? A.Thesenseofsharedidentitymakesnodifference. B.It'snotnecessarytomakeaquickdecision. C.It'simpossibleforstrangerstocooperate. D.Collectiveeffortisinspiring.
Iwasateacherforonlytenyears.In1926onmyreturntoChinaafterfinishingstudiesintheUnitedStatesIbegantoteachatmyalmamaterYenchingUniversityPeipingasalecturerinChinese.TheteachersoftheDepartmentofChinesethenweremostlymyformerteachers. ThestudentsandIweregoodfriends.Thefreshmenweremostlyyoungboysandgirlsagedbetween17and20infiveclasseseachconsistingof30to40studentscomingfromvariousplacesofChina.ThosefromFujianandGuangdonghaddifficultyinunderstandingtheheavilyaccentedspeechofteacherswhocamefromplacessouthoftheYangtzeRiver.Consequentlysomeofthesestudentsweretransferredtomyclassthroughthearrangementsoftheschool'soffice.LookingdownfromtheplatformIwasdelightedbyamultitudeofrosy﹣facedyoungstudentssmilingandstaringcuriouslyatme.TheirsmileswerebynomeansunfamiliartomebeingsimilartothoseIoftensawonthefacesofmyyoungerbrothersandyoungerfemalecousins. Itaughtacourseonadvancedwritingwhichwasanelectiveforstudentsabovethefreshmanlevel.Itgavethematryindifferentgenresofliterarywritingsuchasfictionpoetrycorrespondenceandsometimestranslations.Fortheend﹣of﹣termexaminationIhadthemeachhandinaself﹣editedmagazinespecializinginanysubjectssuchasfineartssportsetc.andcompletewithwelldesignedcoveraimofitspublicationandphotos.Studentsofthesameclasscouldrequestcontributionsorphotosfromeachotherorfromstudentsofotherclasses.Theycalleditaninterestingtry.Themagazinestheyhandedinbytheendofthetermwereverylivelyandencouragingeachhavingitscontentquiteinlinewithitstitle. InrecallingmypastcareerasateacherIalwaysthinkfondlyoftheintimatefriendshipbetweenthestudentsandme.Inthosedaysteachersandstudentsalllivedoncampus.WeoftenwentboatingontheWeimingLakeorhaddiscussionsaboutvariousthingsonthemarbleboatbytheislandinthemiddleoftheLakeorhadheart﹣to﹣heartprivatetalksaboutforinstancejobselectionsormarriage.Allthattookplaceoverhalfacenturyagoandnowmorethanhalfofthemhavegonetoanotherworldbeforeme.Ifeelverysorrowaboutitindeed.Inmymindteachersandstudentsshouldbefriendswithmutualrespectandlove. 25.TheunderlinedwordsalmamaterinParagraph1probablymeans. A.theschoolwherethewriterstudiedbefore B.theschoolthatthewriterdreamtofbefore C.theschoolwherethewritertaughtbefore D.theschoolwherethewriterlivedbefore 26.WhythosestudentsfromFujianandGuangdongweretransferredtomyclass? A.Becausethewriterwasanewteacher. B.Becausetheywantedtotakethecoursethatthewritertaught. C.Becausethewriterwouldliketomakefriendswiththestudents. D.Becausetheycouldn'tunderstandtheheavilyaccentedspeechoftheirteachers. 27.Howdidthewriterfeeltowardshisstudentswhentheyhandedintheirself﹣editedmagazines? A.disappointed B.concerned C.delighted D.unsatisfied 28.Whichoneshouldbethebesttitleofthepassage? A.MyStudents B.JoysoftheTeachingCareer C.AnUnforgettableMemory D.MenLearnWhileTheyTeach.
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短文.短文中共有10处错误每句中最多有两处.错误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∧并在此符号下面写出该加的词. 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. DearShirley I'velearnedyouwanttoknowaboutmyfamilyandyourbedroominyourlastletter.Myparentshadbeenwaitingforthemomentforsuchalongtime.TheyhavepreparedforeverythingyoumayneedduringyourstayinChina.MyelderbrotherLiHuaisafreshmanwhostudyinHebeiUniveristy.Hereallywantstobeyourguidetakeyoutosomepubstolistentomusicorwatchfootballmatch.Mygrandfatherisverykindthathe'swillingtotellyoumuchaboutChinesecultureandhistory.ThebedroomyouwillliveinisjustoppositetomeandthereareaportablecomputerandaTVset.Thedoublebedmaymakeyoufeelmorecomfortablytosleepon.Necessitiesoflifeareavailable.IbelieveinmyfamilyyoucannotonlyhaveenjoyableandunforgettableexperiencebutlearnalotaboutChinathatcangreatlyenrichyourlife.
如图要搭建一个矩形的自行车棚一边靠墙另外三边围栏材料的总长为60m．1怎样围才能使车棚的面积最大2在1中如果可利用的墙壁长为25m怎样围才能使车棚的面积最大
Inwhatcanonlybedescribedasaheroicactagoldenretrievermanagedtosavehisowner'slifebylyingontopofhimforalmost24hourstokeephimfromfreezingtodeathafterslippingoniceandbreakinghisneck. OnNewYear'sEve64﹣year﹣oldBobwhochosenottorevealhislastnameforprivacyreasonsofPetoskeyMichiganwaswatchingafootballgamebetweenClemsonandOhioState.Itwasaround10:30p.m.whenhedecidedtogooutsideandfetchsomemorewoodforhisfireplacewearingonlylongunderpantsslippersandashirt.Hehadtakentheshort15﹣footwalktothefirewoodshedthousandsoftimesbeforebutthistimehispoorchoiceoffootwearmadehimslipandthefalllefthimunabletomove. IwasScreamingforhelpbutmynearestneighborisaboutaquarter﹣mileawayanditwas10:30p.m.butmyKelseycameBobrecalls.BymorningmyvoicewasgoneandIcouldn'tyellforhelpbutKelseydidn'tstopbarking.Shekeptbarkingforhelpbutneverleftmyside.Shekeptmewarmandalert.IknewIhadtoholdonthroughthisandthatwasmychoicetostayalive. 21.WhosavedBob'slife? A.Hisfriend. B.Hisneighbor. C.Hisson. D.Hisdog. 22.WhatwasthereasonforBob'sslipping? A.Heseldomwentoutatnight. B.Hedidn'twearpropershoes. C.Itwastoodarktoseeclearly. D.Theweatherwasfreezingcold. 23.WhatcanbelearnedaboutBobfromthestory? A.Hewasshyinpublic. B.Helikedplayingfootball. C.Helivedallbyhimself. D.Hegotonwellwithneighbors.
Whileyouaretravellingabroadculturalmistakesaremoreseriousthanlinguisticmistakeswhichcanleadtoseriousmisunderstandingandevenill﹣feelingbetweenindividuals.1 ●TouchingSomeone 2InMediterraneancountriesifyoudon'ttouchsomeone'sarmwhentalkingtothemorifyoudon'tgreetthemwithkissesorawarmhugyou'11beconsideredcold.Butbackslap拍背someonewhoisn'tafamilymemberoragoodfriendinKoreaandyou'llmakethemuncomfortable.InThailandtheheadisconsideredsacred﹣neverevenpatachildonthehead. ●TalkingOverDinner InsomecountrieslikeChinaJapanandsomeAfricannationsthefood'sthethingsodon'tstartchattingaboutyourday'sadventureswhileeveryoneelseisdiggingintodinner. 3It'snotbecauseyourgroupisunfriendlybutbecausemealtimesareforeatingnot talking. ●RemovingYourShoesorNot TakeoffyourshoeswhenarrivingatthedoorofaLondondinnerpartyandthehostesswillfindyouuncivilizedbutfailtoremoveyourshoesbeforeenteringahomeinAsiaHawaiiorthePacificIslandsandyou'llbeconsidereddisrespectful.Soifyouseearowofshoesatthedoorstartundoingyourlaces.4 Onceyouareonthegroundofadifferentcountryremainhighlysensitivetonativebehavior.5Anddon'tfeeloffendedifsomethingseemsoffensive﹣likequeuejumping. Afterallthisisaglobalvillageandweareallverydifferent. A.Personalspacevariesasyoutraveltheglobe. B.Asiansconsiderremovingshoesimpoliteathome. C.Neverbecompletelysurprisedbyanything. D.Thelinguisticmistakemeansthatsomeoneisnotfullyexpressinghisidea. E.Lookoutforthefollowingculturalmistakesandtrytoavoidthem. F.Ifnotkeeptheshoeson. G.You'11likelybemetwithsilence.
NooffencetoyoubutscientistshavefoundthatmosquitoesmayfindyourfeetasattractiveasLimburgercheese.Ifthat'syoudon'tfeelembarrassed﹣itdoesn'tmeanyou'renotwashingthemenough.MosquitoesaresimplyattractedbycertainDNA. AUKresearchteamrecentlyinvestigatedthegeneticroleinmosquitoattractionbytestingthebiteappealof18twinsistersand18non﹣twinsisters.Inaseriesoftests20hungrymosquitoeswerereleasedintotheendofaY﹣shapedtubeandallowedtochooseleftorright.Downeitherpathwasonesister'shandreleasingitsdeliciousnaturalodorsbutprotectedfrombitesbehindanetscreen.Aftertestingall36pairsscientistsfoundthatthetwinpairshadconsistentlymoresimilarattractionscoresthanthenon﹣twinonesdid﹣specifically67percentofaperson'sinsectappealhadtodowithhergenes. Sowhat'sthedeal:doesDNAsmell?Thankfullyno.ButspecificDNAdoesattractuniquespeciesofmicrobacteriatoyourbody﹣andthosearewhatmosquitoesjustcan'tresist. Eachofusrightnowiscoveredwithabout100trillionmicrobes微生物outnumberingourhumanDNAtentoone.Maybeweirderstill:scientistsbelieveweshareonlyafractionofthesemicrobialspecieswithoneanothermakingour'microbiome'﹣theworldofbacterialivinginandonus﹣uniquejustlikeourfingerprints.Inadditiontoproducingmanyofthevitaminsandchemicalsinourbloodourmicrobiomeisthoughttoberesponsibleformostofourdistinctodorsaswell. Differentmosquitoespreferdifferentsmellsfromdifferentpartsofthebody﹣that'swhyAnophelesgambiaeknownforspreadingmalariaprefersbitinghandsandfeetwhileothersgorightforthearmpitsorgroin.Andthosesmellscomefromchemicalsproducedbyourmicrobiomes.Sothenexttimeagroupofhungrymosquitoesswarmsyourcousinbutleavesyoubite﹣freethankyourDNAfortheworldofmicroscopiccreaturesonyourskinthatproducejusttherightsmelltokeepthebloodsuckersaway. 32.TheresearchconductedbytheUKteamsuggestedthat. A.moremosquitoeschosethetwinpairs B.moremosquitoeschosethenon﹣twinpairs C.Non﹣twinpairshadmoresimilarattractionthantwinpairs D.mostinsectappealhadtodowithaperson'sDNA 33.WhatdoesthewordthoseinParagraph3referto? A.aspecificDNA B.themicrobateria C.thesmellofbody D.theattractiveblood 34.FromParagraph4wecanlearnthat. A.wearepartofourmicrobiome. B.ourmicrobiomecontributestoourdistinctodors C.ourmicrobiomewilldecideourfingerprintsinsomeway D.ourmicrobiomeproducesvitaminsandnutrientsinourblood 35.Whatdoesthepassagemainlytalkabout? A.Weareattractivetothemosquitoes. B.Differentmosquitoespreferdifferentsmells. C.DNAthatattractsmosquitoesmakesusunique. D.MosquitoesaresimplyattractedbycertainDNA.
BestAll﹣TimeChildren'sBooks Readingtoyourkidsisoneoftheall﹣timebestthingsyoucandowiththemandforthem.Ilovereadingtomykidsandtheylovereadingwithme.Itissomeofthebestqualitytimeeverandsharingagoodbookwithachildisjustawonderfulfeeling. I'velistedofmyall﹣timefavoritechildren'sbooks﹣alistthatcanstartanychild'slibrary.It'sastartingpointtobesure﹣I'msureyoucanthinkofmanymoretobeincluded.ButthesearebooksItrulyloveandmykidsdotooandIthinkmostkidsandparentswilllovethem.Thesearemostlytime﹣testedclassicssotheremightnotbetoomanysurprisesherebutsometimesit'susefultoberemindedofbookswe'veforgottenabout.WheretheWildThing'sArebyMauriceSendak.Icannevergetenoughofthisbook.Itistrulyawesome.Greatdrawingsgreatimagination.IfIhadtochoosejust10booksonthislistthiswouldbeoneofthem. GuessHowMuchILoveYoubySamMcbratney.Iloveyouallthewaytothemoonandback!Funtoreadthiswithyourkidsandthenlatercompetetoseehowmuchyouloveeachother. TheGivingTreebyShelSilverstein.IfSeussisthebestSilversteinisrightbehindhim.IfIhadtolistjust10booksherethisbookwouldbeoneofthem.Suchasweetsadtruebookwithgreatdrawingsofcourse. MatildabyRoaldDahl.PerhapsmyfavoriteDahlbook.WhilereadingthisbookyouwanttohaveMatildaasafriendandduringthetimeyouarewithhersheisyourfriend. CharlieandtheChocolateFactorybyRoaldDahl.Aclassicofcourseandyetanotherpoorkidwhoinevitablyentersyourheart. TheLittlePrincebyAntoinedeSaint﹣Exupery.OriginallypublishedinFrenchthisclassicissouniqueIcannotreallydescribeit.Ifyouhaven'treadittoyourchildpleasedo. MagicTreeHouseSeriesbyMaryPopeOsborne.Averylongseriesover30lasttimeIcountedoffunadventurousandeducationalbooks.Itcoversstuffkidslovelikedinosaursandninjasandknightsandwizardsandmakeshistorycomealive.Mysonisinlovewiththisseries. 21.Thewriterofthispassageprobablyis. A.aprofessor B.aparent C.alawyer D.adirector 22.Whichofthesebookshavethesameauthor? A.WheretheWildThingsAreandGuessHowMuchILoveYou. B.TheGivingTreeandMatilda. C.CharlieandtheChocolateFactoryandTheLittlePrince. D.MatildaandCharlieandt.h.eChocolateFactory. 23.Wecaninferfromthepassagethattheauthor. A.istiredofreadingTheGivingTree B.speakshighlyofSeusswriterofTheGivingTree C.TheLittlePrincewaswritteninEnglishwhenfirstpublished D.therearesomeadventurousstoriesinMagicTreeHouseSeries. 24.Thepurposeofthispassageis. A.topromotesomechildren'sbooks B.togivesomeadviceonhowtoselectachildren'sbook C.tointroducesometime﹣testedchildren'sbooks D.towriteabookreview.
Confidenceisbuiltnotinborn.36Theyseizemorerewardingcareerskeepgoodrelationshipsandjustseemtodoeverythingwithmorestylethantherestofus. Sowhat'stheirself﹣confidence'ssecret?Thereisn'tone.37Andalthoughpeoplewhoareraisedinanencouragingenvironmentwithconfidentrolemodelshaveaheadstartinself﹣confidencedevelopmentweallcanlearntobecomemoreconfidentatanyage. Trythesesimpletipsforpracticingandincreasingyourconfidencelevels: Daretofail.Anybodywho'souttherebravelyperformingisgoingtofailrepeatedly.Ifyou'renotfailingyou'renottrying.Sodon'ttakefailuretoohardortoopersonally38. Dressforsuccess.Youdon'thavetobebeautifultobeconfident.Makethemostofyourownuniquephysicalcharactersandweakenyourdisadvantages. 39You'retheonlypersonwhoknowswhat'srightforyou.Don'tputothers'opinionsaboveyourowninnervoice. Buildaconfidentvocabulary.Stopputtingyourselfdownandgiveupcontinuallyblamingyourtinyweaknesses.Learntoshowupyourstrongpointsandtheworldwilllearntoseeandcelebratethemwithyou. Passonpraise.Praiseothersfortheirvirtuesandstrengths.40. A.Addresspeople B.Listentoyourself C.Peoplewhoshowconfidencereallyseemtohaveitmade. D.Justlearntorollwithitanduseitslessonstokeepimproving. E.Thispracticewillnotdecreaseyourconfidencebuthelpincreaseit. F.Self﹣confidenceisaskillandhabitthatanyonecanlearntodevelop. G.Alwaysblamingotherscanhelpincreaseyourself﹣confidencelevel.
致使试管烧杯等玻璃容器加热时破裂的原因有1玻璃容器外壁有2容器底部跟接触3烧得很热的玻璃容器立即4给烧杯烧瓶加热没有5给试管里的物质加热未先就．
求下列函数的最大值或最小值y=7x²-2x+
下列抛物线有最高点还是最低点写出这些点的坐标抛物线y=3x²-5x+6有最填高或低点该点的坐标是
AEuropeanUnionprogramislettingblindpeopleexperiencefamouspaintingsforthefirsttime.Itusesthreedimensional3﹣Dprintingtore﹣createfamouspaintingssotheycanbetouched. OnepaintingprintedwiththenewtechnologyisGustavKlimt'sTheKiss.ItisapopularattractionattheBelvedereMuseuminViennaAustria.Thepaintingshowsamanandawomanstandinginafieldfilledwithflowers.Theyarewearinggoldrobesandhavetheirarmsaroundeachother.Themanleansdowntokissthewoman. Klimtfinishedthepaintingin1908.Untilnowpeoplewhohadtroubleseeingcouldnot appreciatetheartwork.Butthankstothereproductiontheycantouchthepieceandfeeltheridgesanddepressions.AndreasReichingerstartedmaking3﹣Dversionsofartworkin2010.Hesaidthisreproductionwashismostdifficultprojectbecausethecouple'srobesaresodetailed. DominikaRaditschisablindmuseumvisitor.Shetouchedthereproduction.AsshemovedherhandsarounditshesaidExactlycanyouseethese?Therearesomanydetails.Raditschsaidshecanimaginewhattheoriginalpaintinglookslikewhenshetouchesthereproduction.It'ssomehowround.Youcanfeelit.Youcanfeelit.Itcomeswithit.Andinmanyplacesit'ssosmooth.AndthenIthinktomyself:itprobablyshinestoo!Raditschsaid. TheBelvedereisnottheonlymuseumtohave3﹣Dversionsofitsartwork.SomeofthepiecesatthePradoinMadridSpainhavereproductionsthatcanbetouched.ButthepieceinViennahasonespecialpart:Itismadewithwidelyavailable3﹣Dprintingtechnology.Thatmeansonedayblindartfansanywhereintheworldcoulddownloadthesourcefilesandprintthereproductionsthemselves. 28.WhatisThekiss? A.AEuropeanUnionproject. B.Apopularpainting. C.A3﹣Dtechnology. D.Afamousmuseum. 29.WhydidReichingersaythisreproductionwasdifficulttofinish? A.Thepaintingwasreproduceddetailedly. B.Theoriginalartworkwasmadein1908. C.Blindartfanscan'tdownloadthesource. D.The3﹣Dtechnologyisnotavailable. 30.HowdidRaditschfeelwhenshefirsttouchedthereproduction? A.Awkward. B.Puzzled. C.Excited. D.Nervous. 31.Whatisthebesttitleforthetext? A.AEuropeanUnionProgramforMuseumVisitors B.3﹣DPrintingLetsBlindExperienceFamousPainting C.HowtoReproducetheWorld﹣famousPaintings D.ASpecialMuseumforArtFansinViennaAustria.
下列抛物线有最高点还是最低点写出这些点的坐标抛物线y=-4x²-9x有最填高或低点该点的坐标是
IntheUSAthehighschoolgraduationceremonyisveryimportant.12th﹣gradestudentsorseniorswhoareabout17or18yearsoldlookforward61thisevent.ThegraduationceremonyitselftakesplaceattheendofMayor62beginofJune.Theceremonyusuallyincludesmusicawardsandaguestspeaker.Afterthespeechesstudentswalktothefrontoftheroom63receivetheirdiplomasfromtheheadmaster.Studentsstartpreparingforgraduationalongtime64ithappens.Theyorderthingsdesigned65especialfortheirclass. Anothertraditionistohavetheirphotographstaken.Thesephotographsareusedfortheclassyearbookwhichisa66printbookaboutallthestudentsintheschoolbutwithmostofthepagesabouttheseniors.Studentshavespecialcardscalledannouncementsprintedtosendtofriendsandrelativestotell67theyabouttheirgraduation.Thecardsoftenincludean68invitetotheceremony.Ifyoureceive69announcementyoushouldsendapresentormoneytothegraduate.Aftertheceremonyfamiliesusuallyhavegraduationpartiesforfriendsandrelatives.Itisadayandanight70highschoolseniorsrememberforalongtime.
求下列函数的最大值或最小值．y=x²-3x+4
YearsagoIwasdrivingmythree﹣year﹣olddaughtertoherfirstdayofpreschoolinPrinceton41theradiohostsaidAplanehasjust42oneoftheWorldTradeCentertowers.Not43whatIhadheardIwalkedmydaughtertoherclassroom.Iwasbackinmy44withmyone﹣year﹣oldsongettingreadyto45whenthenewsbrokeaboutasecondplanehittingtheWorldTradeCenter.ThatwaswhenIwasthrownintogreatfear﹣my46workedinTowerOne. Aminutelatermycellphonerang.ItwasmyclosefriendJennifer.Idon'tthinkIcan47.Itoldher.StaythereJennifersaidIamonmyway.Within48shewasintheparkinglot停车场49todrivemehome.MyotherfriendsMaureenandLorirushedtomyhouse50.ThethreeofthemwereholdingmewithforceaswewatchedTowerOne51ontelevisionandIcriedmyhusband'sname. Noneofthem52whattosaytomeonthatdayorthefollowingdays.53theyknewwhattodo.WhenIneededtobehugged拥抱theyhuggedme.WhenIneededtobeleft54theygavemespace.Theyweregoingtodo55theycouldtomakesuremychildrenandIgot56this. MyfriendswerethereformeinwaysIcouldn'thaveimagined.Theycreateda57sothatsomeonecouldliewithmeatnightuntilIwas58.Mealsweresenttomyhomedaily.59andclothingforthekidscameinlargenumbers.IreallyfeelgratefulforthesekindpeoplewithoutwhomIwouldn'thavelivedthroughmy60. 41.A.while B.when C.as D.since 42.A.trapped B.removed C.struck D.entered 43.A.knowing B.considering C.minding D.believing 44.A.apartment.B.house C.car D.yard 45.A.leave B.arrive C.move D.stop 46.A.mother B.husband C.father D.brother 47.A.drive B.walk C.stand D.run 48.A.weeks Bhours C.days D.minutes 49.A.active B.willing C.ready D.determined 50.A.gradually B.quickly C.finally D.suddenly 51.A.appear B.fail C.stand D.fall 52.A.realized B.knew C.understood D.cared 53.A.Besides B.Therefore C.Otherwise D.However 54.A.out B.behind C.alone D.aside 55.A.something B.anything C.everything D.nothing 56.A.into B.down C.through D.across 57.A.schedule B.plan C.program D.rule 58.A.easy B.pleased C.calm D.asleep 59.A.Flowers B.Pets C.Toys D.Drinks 60.A.suffering B.experience C.illness D.journey
热门题库
更多
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
高二下学期化学
高二下学期生物
高三下学期生物
高三下学期化学
高三上学期英语
高二下学期英语
教案备课库
高三下学期英语
教案备课库
教案备课库
教案备课库
教案备课库
湘公网安备 43130202000226号