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为了测量一个量程为3.0V的直流电压表的内阻RV（约为几千欧），所用的电路如图甲所示．（1）请将图乙的器材连成完整的电路；（2）该实验中需要进行的步骤罗列如下，合理的顺序是 （用步骤前的字母表示...
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用伏安法测量一个定值电阻的电阻值现有的器材规格如下A.待测电阻Rx大约100ΩB.直流毫安表A1量程
一个量程为1.5V的电压表其表头内阻为300Ω现需要用该电压表测量30V的电压需要串联多大的电阻才能
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.用伏安法测量一个定值电阻的电阻值现有的器材规格如下A.待测电阻Rx大约100ΩB.直流毫安表A1量
用伏安法测量一个定值电阻的电阻值现有的器材规格如下A.待测电阻Rx大约100ΩB.直流毫安表A1量程
用准确度为1.5级量程为30V的电压表测量20V的直流电压问绝对误差和相对误差各为多少若采用准确度为
用伏安法测量一个定值电阻的电阻值现有的器材规格如下A.待测电阻Rx大约100ΩB.直流毫安表A1量程
用伏安法测量一个定值电阻的电阻值现有的器材规格如下A.待测电阻Rx大约100ΩB.直流毫安表A1量程
测量20V的直流电压如果选用准确度为1.5级量限为30V的电压表;或选 用准确度为0.5级量限为15
某物理兴趣小组要精确测量某电压表的内阻实验室可供选择的器材如下待测电压表V.量程2V内阻约为4kΩ毫
为测量一电源的电动势及内阻在下列三个电压表中选一个改装成量程为9V的电压表A．量程为1V内阻大约为1
在描绘小灯泡的伏安特性曲线的实验中现除了有一个标有5V2.5W的小灯泡导线和开关外还有A.直流电源电
用伏安法测量一个定值电阻的电阻值现有的器材规格如下A.待测电阻Rx大约100ΩB.直流毫安表A1量程
11分如图所示为用伏安法测量一个定值电阻阻值的实验所需器材实物图器材规格如下①待测电阻Rx约l00Ω
在描绘小灯泡的伏安特性曲线的实验中现除了有一个标有5V2.5W的小灯泡导线和开关外还有A.直流电源电
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在描绘小灯泡的伏安特性曲线的实验中现除了有一个标有5V2.5w的小灯泡导线和开关外还有A.直流电源电
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下列说法中正确的是
10分英语课上老师要求同学相互修改作文.假设以下文章为你同桌所写请你对其进行修改.文章中共有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:在缺词处加一个漏词符号∧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. Alicewasnotontimeforschoolinthismorning.Shelookedlittletiredwhenshemetherchemistry'steacherMissGreen.Sheapologizedforherbeinglately.MissGreenaskedheriftherewassomethingwrongwithher.Thegirlsaidthathewasallrightsoshedidn'thavemuchsleeplastnight.Shewenttoafootballgameandtooksomepictures.Aftershegothomeshewasbusydevelopedthem.Shestayeduptillmidnight.MissGreentoldhertogetmoresleepatnight.Alicepromisesnottodothatagain.ThenAliceshowedMissGreenherbeautifulpicture.
木质素是制浆造纸工业的副产物具有优良的物理化学特点若得不到充分利用变成了制浆造纸工业中的主要污染源之一不仅造成严重的环境污染而且也造成资源的重大浪费．木质素的一种单体结构简式如右图所示下列说法错误的是
30分RecentlyIpaidavisittoHarvardUniversitywheretherearetopclassscientistsandprofessorsandthebestacademicsystemintheworld. Iwasvery1whenIfirststeppedintothecampus校园.Wellit'snotevenreallyacampus.It's2likeanareainasmalltown.Harvard'smainbuildingsarefromthe18thcentury.Theylookveryoldand3.Youmight4saythey'realittleshabby破旧.Theydon'tfitthemodern5ofuniversityatall.Thebuildingsare6byflowersandtreessoIfeltasifIhadwalkedintoacastleoftheMid﹣Ages.ButwhenIlookedacrossthestreetthe7shopsandin﹣fashion时尚的studentsmademefeellikeIwasinthe21stcentury8.Itcreatesastrongcontrast对比andbringsaspecial9Ourtour10Garytookusaroundandtoldus.Youseethisgrassfieldinthecenteroftheschool?Hereiswheretheyholdtheir11ceremony仪式礼节.Theyjustsetuptentsandbenchesandhaveaverysimpleceremony.It's12!Whowouldthinkthemosttalentedstudentsjustgraduateonthegrass? I13somestudentsputablanketonthegrassandliedowntoreadabook.WhenIlistenedtothesoftsoundof14turningalongwiththesingingofthebirdsIfeltvery15.Therewasnocompetitivefeelingatall. Harvardhastheworld'sfirstcomputerinitssciencecentre16therearehundredsofhigh﹣endcomputerstoo.Itsreligionandtheliterature文学departmentsarealso17thebest.Itistheperfectmixoftraditionand18technology.ItmakesHarvardaveryattractiveplaceto19in. IhopeonedayI'll20mydreamschool﹣﹣﹣Harvard. 1.A.excited B.troubled C.shocked D.tired 2.A.more B.less C.little D.most 3.A.great B.solid C.noisy D.simple 4.A.still B.even C.ever D.yet 5.A.model B.way C.idea D.example 6.A.filled B.recovered C.surrounded D.floated 7.A.empty B.quiet C.free D.busy 8.A.once B.again C.only D.then 9.A.environment B.view C.atmosphere D.condition 10.A.guide B.partner C.visitor D.professor 11.A.celebration B.closing C.opening D.graduation 12.A.uninteresting B.unbelievable C.unbearable D.uncomfortable13.A.had B.saw C.felt D.imagined 14.A.books B.benches C.blankets D.pages 15.A.lucky B.calm C.nervous D.puzzled 16.A.but B.and C.though D.yet 17.A.among B.about C.to D.under 18.A.old B.new C.fast D.fresh 19.A.travel B.live C.study D.tour 20.A.serve B.visit C.find D.attend
在容积为2.0L的密闭容器内物质D在T℃时发生反应其反应物和生成物的物质的量随时间t的变化关系如右图据图回答下列问题 1从反应开始到第一次达到平衡时A物质的平均反应速率为mol/L•min． 2根据右图写出该反应的化学方程式该反应的平衡常数表达式为K＝． 3第5分钟时升高温度ABD的物质的量变化如右图则该反应的正反应是填“放热”或“吸热”反应反应的平衡常数填“增大”“减小”或“不变”．下同B的反应速率． 4若在第7分钟时增加D的物质的量A的物质的量变化正确的是用图中abc的编号回答
下列有机物系统命名正确的是
10分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. WhennewscamethatIwasnotchosenasthememberofthevolleyballteamIwassuchfrustratedthatIalmostdecidedtogiveup.HowevermybestfriendMirandaanalyzedmyproblemspointedoutthatmylazinessandpoorpreparationledmyfailure.FromthenonIdevotedallmysparetimetopracticeplayingandconsultinghisteachersaboutskillseveryday.WhenanotherchancecameIhadgotfullyprepared.AsaresultofIwasselectedandbecameoneofthemostimportantplayerinourschoolteam.FromthisstoryIamdefiniteconvincedthatthebetterpreparedwearethemuchlikelyweareabletoachieveourgoals.
实验室中准备有以下主要仪器及用品大试管带导管的单孔塞药匙镊子水槽集气瓶玻璃片酒精灯铁架台如果药品选用合理用以上仪器用品能完成的实验有
两种一元碱MOH和ROH的溶液分别加水稀释溶液pH的变化如图所示下列叙述不正确的是
某反应池中发生“生物硝化过程”利用O2将NH4+氧化成NO3﹣如果不考虑过程中硝化细菌的增殖其净反应如下式所示 +++ 完成上述反应的离子方程式并配平将系数填入方框中并标出电子的转移方向和数目． 1反应中还原剂是被还原的元素是． 2将铵态氮中的lmg氮转化成硝酸根中的氮需氧气mg．精确到0.01 3取100mL完全反应以后的溶液加入19.2g铜粉及一定量的稀硫酸恰好完全反应假设还原产物全部是NO气体则原溶液中NH4+的浓度为mol/L．假设反应前后溶液的体积不变
10分 Flavoring Mostdrinksstatingthattheyarefruit﹣flavored水果味道的containnofruitatallwhilemostoftherestcontainonlyasmallquantityoffruitaccordingtoastudycarriedbytheBritishFoodCommission. Shoppersneedtocheckthelabels标签beforebuyingdrinksthoughsometimestheactualcontentcanbenon﹣existentsaidFoodCommissionspokespersonIanTokelove.Foodproductionishighlycompetitive.1Itwillincreaseprofitsandconsumerswon'talwaysrealizetheyarebeingtricked. Flavoringsarefocusedontheflavorsofnaturalfoodproductssuchasfruitsmeatsandvegetablesorcreatingflavorforfoodproductsthatdonothavethedesiredflavors.Researchersanalyzedthecontentsof28strawberry﹣flavoredproductssoldinstores.2Ofthe11productsthatdidcontainstrawberriesfiveofthemcontainedlessthanonepercentrealfruit.Inadditioneachjuiceboxcontainednearlyeightteaspoonsofsugar. 3Let'stakejamasanexample.Somestrawberry﹣flavoredjamwaslabeledascontainingnoartificialcolorsflavorsorsweetenersbutitcontainedabsolutelynostrawberriesatall. 4Consumershavetherightstoknowclearlyaboutwhattheyhavebought.UndercurrentUKlawfoodpackagesdonothavetodistinguishbetweennaturalandartificialflavoring.Describingaproductasstrawberryflavorandcoveringthesurfaceofthepacketwithpicturesofstrawberriesismisleading.5UnfortunatelyitisalsolegalandwidespreadTokelovesaid.It'stimetotakemeasurestoprotecttheconsumers'rights. A.Theproductswhichcontainrealfruitarepopularwithpeople. B.Evenproductsadvertisedasmorenaturaloftencontainednofruit. C.Theyfoundthatabout60vpercentofthemdidn'tcontainanyfruitatall. D.Ifcompaniescancuttheircostsbyusingflavoringtheyarelikelytodoso. E.Itisimportantandneessarytodemandasmallamountofflavoringintheproducts. F.Actuallytheproductcontainsjustatinypercentageofstrawberryorevennofruitatall. G.TheFoodCommissionsuggestedallflavorsusedinaproductshouldbelistedonthepackaging. 1. 2. 3. 4. 5.
常温下浓度均为0.1mol/L的三种溶液①CH3COOH溶液②NaOH溶液③CH3COONa溶液下列说法中不正确的是忽略混合前后溶液体积变化
8分Howfarwouldyoubewillingtogotosatisfyyourneedtoknow?Farenoughtofindoutyourpossibilityofdyingfromaterribledisease?Thesedaysthat'smorethananacademicquestionasTracySmithreportsinourCoverStory. Therearenowmorethanathousandgenetic基因的testsforeverythingfrombaldnesstobreastcancerandthelistisgrowing.Questionisdoyoureallywanttoknowwhatmighteventuallykillyou?ForinstanceNobelPrize﹣winningscientistJamesWatsononeofthefirstpeopletomaptheirentiregeneticmakeupissaidtohaveaskednottobetoldifhewereatahigherriskforAlzheimer老年痴呆症. IfItellyouthatyouhaveanincreasedriskofgettingaterriblediseasethatcouldweighonyourmindandmakeyouanxiousthroughwhichyouseetherestofyourlifeasyouwaitforthatdiseasetohityou.ItcouldreallymessyouupsaidDr.RobertGreenaHarvardgeneticist. EveryacheandpainSmithsuggestedcouldbeunderstoodasthebeginningoftheend.That'sright.IfyoueverworriedyouwereatriskforAlzheimer'sdiseasetheneverytimeyoucan'tfindyourcarintheparkinglotyouthinkthediseasehasstarted. Dr.Greenhasbeenthinkingaboutthisissueforyears.HeledastudyofpeoplewhowantedtoknowiftheywereatahighergeneticriskforAlzheimer's.Itwasthoughtthatpeoplewhogotbadnewswouldforlackofabettermedicaltermfreakout.ButGreenandhisteamfoundthattherewasnosignificantdifferencebetweenhowpeoplehandledgoodnewsandpossiblytheworstnewsoftheirlives.Infactmostpeoplethinktheycanhandleit.PeoplewhoaskfortheinformationusuallycanhandletheinformationgoodorbadsaidGreen. 1.Thefirstparagraphismeantto. A.asksomequestions B.introducethetopic C.satisfyreaders'curiosity D.describeanacademicfact 2.WhichofthefollowingistrueofJamesWatson? A.Heisstronglyinfavorofthepresentgenetictests. B.HeismorelikelytosufferfromAlzheimer'sdisease. C.Hebelievesgeneticmappingcanhelpcureanydisease. D.Hedoesn'twanttoknowhischanceofgettingadisease. 3.TheunderlinedpartfreakoutinParagraph5isclosestinmeaningto. A.breakdown B.dropout C.leaveoff D.turnaway 4.ThestudyledbyDr.Greenindicatesthatpeople. A.prefertoheargoodnews B.tendtofindoutthetruth C.canacceptsomebadnews D.havetherighttobeinformed
30分AtfirstpeopleintheUSthoughtEbola埃博拉wasonlyadiseaseaccompaniedwithfeverandfoundinAfricaatthebeginning.1thenamanfromwestAfricadiedfromEbolaatahospitalinDallasTexas.Andtwonurses2forhimbecameinfected感染withtheviruswhichmadetheUSgovernmentpublishnewguidelinesto3healthworkers. TopAmerican4haverepeatedlysaidthatmostpeoplehavelittlechanceofbeinginfected.Expertshave5thatEbolacanonlybespreadthroughinfectedperson'sbodyfluids﹣likeblood.Butit6thatmanyAmericansare7whattheyhaveheard. Arecentsurveyfoundmorethan80percentofAmericansbelievethatEbolacanbespreadinmany8includingairforcedthroughthenoseormouth.BesidestheHarvardSchoolofPublicHealth9thefindings.Thestudyalsoshowedthatmostadultsfeartherewillbean10ofEbolaintheUnitedStatessoon.11surveyfoundthatmorethan70percentofAmericanswouldsupportcallsto12traveltoandfromEbola﹣affectedpartsofAfrica. ThomasFriedenheadstheU.S.CentersforDiseaseControlandPrevention.Whenaskedwhether 13officialshadconsideredatravelbanMr.Friedenhad14tosay:Wewon'tbeabletochecktravelersfor15whentheyleaveorwhentheyarrive.Wewon'tbeableaswedo16totakeadetailedhistorytoseeiftheywere17whentheyarrive.Whenthey18wewouldn'tbeabletoimposequarantine强加隔离aswenowcaniftheyhavehigh﹣risktouch. LastweekPresidentBarackObamaurgedAmericansnotto19whathecalledpanicorfear.ThisweektheadministrationannouncedthatalltravelersreachingtheUnitedStatesfromsomeAfricannationsare20topassthroughoneoffiveairports. 1.A.Just B.Yet C.So D.Even 2.A.arranging B.caring C.searching D.standing 3.A.treat B.attend C.inspec tD.protect 4.A.policemen B.officers C.physicists D.doctors 5.A.stated B.suggested C.considered D.regretted 6.A.proves B.happens C.says D.appears 7.A.studying B.discussing C.questioning D.determining 8.A.ways B.areas C.organs D.countries 9.A.announced B.received C.realized D.rejected 10.A.increase B.income C.decrease D.outbreak 11.A.Theother B.Another C.Thesame D.One 12.A.forbid B.expect C.require D.allow 13.A.foreign B.royal C.African D.federal 14.A.that B.this C.nothing D.those 15.A.change B.money C.fever D.crime 16.A.immediately B.previously C.presently D.regularly 17.A.examined B.searched C.explored D.exposed 18.A.leave B.arrive C.live D.stay 19.A.lookforwardto B.payattentionto C.giveinto D.addupto 20.A.persuaded B.required C.advised D.guided
将Fe和Fe2O3的混合物加入25mL2mol/L的HNO3溶液中反应完全后无固体剩余生成224mLNO气体标准状况再向反应后的溶液中加入1mol/L的NaOH溶液要使铁元素全部沉淀下来所加NaOH溶液的体积至少是
8分Aslifeexpectancyincreasesnowadaystheaveragepersonliveswellbeyondtheageofretirement.Asaresulttheelderlymakeupanever﹣increasingpercentageofsocietywhichmakesitmoreimportantthaneverforarealefforttobemadeinimprovingthelivesofseniorcitizens. Onewaytodealwiththesituationwouldbetoensurethattheelderlyhaveenoughmoneyonwhichtolive.Obviouslywhenapersonstopsworkingtheystillrequireasourceofincometocovertheirbasicneedssuchasfoodaccommodationandheating.Aclearsolutiontotheproblemisforthegovernmenttomakesurethatthestatepensionisadequatefortheseneeds. Stepsshouldalsobetakentoovercomethehealthproblemstheelderlyface.Thegovernmentshouldalsoprovideaccesstothebesthealthcareavailablewhichmaynecessitatepayingforresidentialhomeswheretheelderlycanhaveround﹣the﹣clocknursingorattheveryleastprovidingmedicationfreeofchargetoallpeopleoveracertainage. Thelivesofoldpeoplecouldbeimprovedifattemptsweremadetoaddresstheproblemofsocialisolation.Ifweorganisedtripsfortheelderlytocommunitycentresvisitsfromsocialworkerstheirproblemoflonelinesscanbereducedalotwhichmarksthelivesofsomanyoldpeoplelivingaloneandfarfromtheirfamilies. Onefinalsuggestionwhichwouldhelpenormouslyistochangetheattitudeofthecommunitytowardsitsoldermemberswhoarealltoooftenseenasaburdenonsocietyanddismissedashavinglittletodowithmodernlife.Weneedtobetaughtfromanearlyagetorespecttheviewsofoldpeopleandappreciatetheirbroaderexperienceoflife.Thiswouldhelpsocietyasawholeandencourageappreciationoftherolethatoldpeoplecanstillplaytoday. 1.Whatdoesthepassagemainlytalkabout? A.Alltheelderlycanenjoyfreemedication. B.Thenursescantakegoodcareoftheelderly. C.Somesuggestionswouldbemadetoimprovethelivesoftheelderly. D.Thehealthcareavailabletotheelderlyisgood. 2.TheunderlinedwordaddressinParagraph4probablymeans. A.findout B.dealwith C.putdown D.pickup 3.Whatfactorsaffectedtheoldpeople'slife? a.thestatepension b.thebasicneeds c.theattitudeofthecommunity d.theexperienceoflife e.socialisolation f.medicalcare A.abcd B.bcde C.cdef D.acef 4.Accordingtothelastsuggestiontheoldpeople. A.shouldberespectedbyallofus B.havetogathermorelifeexperience C.mayberegardedasourheavyburden D.mustchangetheirattitudetothecommunity
由苯合成香料K和解热镇痛药物G的路线如下 已知 请回答 1芳香烃A中CH原子数之比是451molA在氧气中完全燃烧生成8molCO2A的分子式是A的结构简式是． 2B→K的反应类型是． 3B的结构简式是． 4D→E反应的化学方程式是． 5K与新制CuOH2悬浊液反应的化学方程式是． 6G与第5小题中反应的有机产物互为同分异构体含有相同的官能团且位置与F中官能团的位置相同G的结构简式是．
6分EachmorningGrandpawasupearlysittingatthekitchentablereadinghisbook.Hisgrandsonwantedtobejustlikehimandtriedtocopyhimineverywayhecould.OnedaythegrandsonaskedGrandpaItrytoreadthebookjustlikeyoubutIdon'tunderstanditandIforgetwhatIunderstandassoonasIclosethebook.Whatgooddoesreadingthebookdo? ThegrandpaquietlyturnedfromputtingcoalinthestoveandrepliedTakethiscoalbasketdowntotheriverandbringmebackabasketofwater.Theboydidashewastoldbutallthewaterleakedoutbeforehegotbacktothehouse.ThegrandpalaughedandsaidYou'llhavetomovealittlefasternexttimeandsenthimbacktotheriverwiththebaskettotryagain. Thistimetheboyranfasterbutagainthebasketwasemptybeforehereturned.Outofbreathhetoldhisgrandpathatitwasimpossibletocarrywaterinabasketsohewenttogetabucketinstead.ThegrandpasaidIdon'twantabucketofwater;Iwantabasketofwater.You'rejustnottryinghardenough. Theboyagaindippedthebasketintotheriverandranhardbutwhenhereachedhisgrandpathebasketwasemptyagain.OutofbreathhesaidGrandpait'suseless!Soyouthinkitisuseless?thegrandpasaidLookatthebasket. Theboylookedatthebasketandforthefirsttimeherealizedthatthebasketwasdifferent.Ithadbeentransformedfromadirtyoldcoalbasketandwasnowclean.Grandsonthat'swhathappenswhenyoureadthebook.Youmightnotunderstandorremembereverythingbutwhenyoureadityou'llbechangedinsideandout. 1.Whatpuzzledthegrandsonmostwas. A.whetheritwasusefultoreadbooks B.whyheforgotwhathereadsoon C.whatkindofbookhecouldunderstand D.howhecouldreadbookslikehisgrandpa 2.WhydidGrandpaaskhisgrandsontofetchabasketofwater? A.Totrainhimtorunfaster. B.Tocleanthedirtybasketintheriver. C.Topunishhimfornotreadingcarefully. D.Togethimtorealizetheuseofreadingbooks. 3.Whatlessoncanwelearnfromthestory? A.Theoldarealwayswiserthantheyoung. B.Itisfoolishtocarrywaterwithabasket. C.Readingbookscanchangeapersongradually. D.Youcan'texpecttorememberwhateveryouread.
下列离子方程式书写正确的是
实验室可以长期放置的试剂是
PM2.5是指大气中直径小于或等于2.5微米的颗粒物也叫可入肺颗粒物与肺癌哮喘等疾病的发生密切相关是灰霾天气的主要原因．它主要来自化石燃料的燃烧如机动车尾气燃煤等．下列与PM2.5相关的说法不正确的是
10分Justlikechildrenbabyanimalsspendcountlesshoursatplay.Afterstudyinganimalplayformanyyearsscientistsrecognizethatyounganimalplayispracticeforadultbehavior.Todaythisplayisroughlydividedintothefollowinggroups. Locomotorplayreferstothemovementsanimalscarryoutintheirplay.Runningleapingturningandkickingaresomeofthemostcommonexamplesoflocomotorplay.Anadultdeermayrunleapandtwisttoescapeitsattackers.Playmovementslikethesesurelymakeyounganimalsnimble.Somedaytheseskillsmighthelpsavetheirlives. Movingforwardslowlyattackingsuddenlyandbitingareexamplesofpredatoryplaythathelpyoungpredatorsprepareforalifeofrunningafterandtakingholdofotheranimals.Wildcatswolvesandbearsarepredators.Itisverycommontoseetheseyounganimalsplaythiskindofgameswhichsharpentheirskillsandteachthemabouttheirstrengthsandlimitations. Forchildrenplayingwithtoysisbothfunandeducational.Ithelpsimprovetheirhandandeyemovementsaswellasdevelophandskillstoaccomplishtasks.Itisthesamewithanimals.Youngchimpanzeesimprovetheirhandskillswhileplayingwithsticks.Birdsalsoplaywiththingsinwaysthatteach.Swallowsdropandrecoverfeathersinmidair.Divingsuddenlytocatchthefeathersisagoodpracticeforcatchingflyinginsects. Socialplayhelpsanimalslearnhowtobehavewhentheyrunintootheranimals.Anditteachesanimalsaboutcommunication.Ananimalgivessignalstoletanotheranimalknowitwantstoplay.Manyanimalsgivesignalsbyshowingaplayface.Insomewaysthisfaceislikeahumansmile;theanimalholdsitsmouthinarelaxedandopenmanner.Duringplay﹣fightssomeanimalsmaystepbackwardstosignalthattheyareplayingandnotactingseriously. Untilnowscientistshaveunderstoodplayfulactshelpprepareanimalsfortheirseriousadultsituations.Butthenumbersofplayfulspeciesandexamplesofanimalplayarevast.Thepurposeofanimalplaymayhavemeaningsscientistshavenotdiscoveredyet. 1.Themainpurposeofthetextisto. A.askustotakegoodcareofwildanimals B.encourageustolearnmoreaboutanimals C.entertainuswithinterestinganimalstories D.showussomethingaboutanimalbehavior 2.TheunderlinedwordnimbleinParagraph2canbestbereplacedby. A.cruel B.swift C.curious D.strong 3.Whichofthefollowingbelongstopredatoryplay? A.Adeerrunsleapsandturns. B.Achimpanzeeplayswithastick. C.Alionmovesslowlyandmakesanattacksuddenly. D.Adogholdsitsmouthinarelaxedandopenmanner. 4.BasedonParagraph5aplayfaceis. A.atypeofsignalbetweenanimals B.anameforakindofanimalplay C.anactivitythatinvolvesadultanimals D.anactionthatistaughttoanotheranimal 5.Whichofthefollowingshowsthestructureofthetext?
下列分离或提纯物质的方法正确的是
15分Agroupoffrogsweretravelingthroughthewoodsandtwoofthem1fallintoahole.Alltheotherfrogslookeddown.Whentheysawhowdeep2holewastheytoldthetwofrogsthattheywoulddiesoon. Atfirstbothofthetwofrogsdidn'tcaretheirwordsandtried3besttojumpoutofthehole.Theotherfrogskepttellingthemtostopbecausetheythoughttherewasnochance4jumpoutofsuchadeephole.Finallyoneofthetwofrogsbelievedthesewordsandgaveup.Hefelldownanddied. Theotherfrogcontinuedtojumpashardashecould.Onceagainthecrowdoffrogsshoutedathimtostopthepainandjustdie.Hejumpedeven5hardandfinallysucceeded.WhenhegotouttheotherfrogsaskedDidn'tyouhearus?6theirgreatsurprisethefrogturnedouttobedeaf.Hethoughttheywerehelpinghimallthetimenot7stophim. Thisstoryteachestwolessons:Thereispoweroflifeanddeathinthetongue.Well﹣meantwordscanhelppeopleintrouble.Butevilwordssometimescankillthem.Becarefulof8yousay. Rememberthepowerofwords.Anyonecanspeakwords9arelikelytomakepeoplegiveupindifficult10time. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
设NA表示阿伏加德罗常数下列叙述中正确的是
6分Noonewouldmuchliketheideaofeating61poundsoftomatoesaday.Butiftheirgoodnesswasputintoaneasy﹣to﹣swallowpillthatyouweretoldmightpreventstrokes中风andheartattacksyouwouldprobablybeputtinginanordertomorrow. Researchersbelievetheymayhavecomeupwithjustthataftertrials.Thedailypillcontainsachemicalcalledlycopenewhichmakestomatoesredandisknowntobreakdownfatinthevessels血管.ACambridgeUniversitystudyfoundtakingthepillsimprovedbloodflowandtheliningofvesselsinpatientswithpre﹣existingheartconditions.Italsoincreasedtheflexibilityoftheirvesselsby50percent.Thescientistsbelieveitcouldlimitthedamagecausedbyheartdisease﹣responsiblefor180000deathsayear﹣andhelpcutthe49000deathsayearfromstrokes.Theyalsohopeitcouldbenefitthosewitharthritis关节炎diabetes糖尿病andevenslowtheprogressofcancer. Eachpillisequaltoeatingaround61poundsofripetomatoes.StudieshaveshowneatingaMediterranean﹣styledietrichintomatoesfishvegetablesnutsandoliveoilcansignificantlyreducecholesterol胆固醇andhelppreventcardiovasculardisease. Preliminaryresultsfromatwo﹣monthtrialinwhichthepillwasgivento36heartdiseasepatientsand36healthyvolunteerswithanaverageageof67werepresentedatameetingoftheAmericanHeartAssociation.Itwasshowntoimprovethefunctionoftheendothelium﹣thelayerofcellsliningbloodvessels.Italsoimprovedtheirsensitivitytonitricoxidethegaswhichcausestheenlargementofthevesselsinresponsetoexercise. IanWilkinsonheadofCambridgeUniversity'sclinicaltrialsunitsaidTheseresultsarepotentiallyverysignificantanditmeetsthegoalbutweneedmoretrialstoseeiftheytranslateintofewerheartattacksandstrokes. Furtherstudiesareplannedwithresearchershopingitcouldofferachoiceforheartdiseasesuffererswhocannottakethecholesterol﹣lowingdrugs. MikeKnaptonheadoftheBritishHeartFoundationsaidAlthoughthisshowedlycopeneimprovedbloodflowinpeoplewithheartdiseasethat'salongwayfromdemonstratingthattakingitcouldimproveoutcomesforpeoplewithheartdisease.Thebestwaytogetthebenefitsofagooddietistoeatplentyoffreshfruitandvegetables. 1.WhatcanweinferfromParagraph1? A.Wecaneattoomuchtomatofood. B.Tomatoesarehelpfultostrokesandheartattacks. C.Tomatoeswilllosehealthyelementswereputintopills. D.Wehadbetternoteattomatoes. 2.Wecanlearnfromthepassagethatthepills. A.areattheexperimentstage B.cancureallthedisease C.arewidelyusedamongpatients D.costpatientssolittlemoney 3.WhatWasIanWilkinson'sopiniononthetrial? A.Disappointing. B.Surprising. C.Satisfactory. D.Terrible.
下列关于合成材料的说法中不正确的是
如图所示的实验能达到实验目的是
25分假定你是希望中学学生李华得知2017年香港大学要在大陆进行自主招生的消息后有意向香港大学申请参加自主招生考试请用英语写一封自荐信主要包括:1.个人信息2.性格爱好与特长3.学习情况注意:1.词数100左右;2.信的开头已为你写好不计入总词数;3.可根据内容要点适当增加细节以使行文连贯.4.参考词汇:自主招生independentrecruitmentDearSirMynameisLiHuafromHopeHighSchool.YoursLiHua.
三聚氰胺化学式C3N6H6是一种非食品类的重要有机化工原料广泛用于塑料造纸建材等行业．下图是我国科技工作者研制的以尿素为原料生产三聚氰胺的工艺﹣﹣“常压气相一步法联产纯碱新技术” 已知①尿素的熔点是132.7℃常压下超过160℃即可分解 ②三聚氰胺的熔点是354℃加热易升华微溶于水 ③以尿素为原料生产三聚氰胺的原理是6CONH22C3N6H6+6NH3+3CO2 请回答 1尿素是一种常用含氮量最高的化肥其氮元素的质量百分数为在实验室使其熔化的容器名称叫． 2工业上合成尿素的化学反应方程式为反应条件可以不写 3写出各主要成份的化学式产品1产品2X 4联氨系统沉淀池中发生的化学反应方程式为 5为了使母液中析出更多的产品2常用的方法是 A加入固体NaClB加入固体NaHCO3C通入CO2气体D通入NH3 6若生产过程中有4%的尿素损耗每吨尿素可生产三聚氰胺吨副产品纯碱吨．精确到0.001
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