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重铬酸钾常用作有机合成的氧化剂和催化剂等．由含铬废液（主要含Cr3+、Fe3+、K+、SO42﹣等）制备K2Cr2O7的流程如图所示． 已知：Ⅰ在酸性条件下，H2O2能将Cr2O72﹣还原为Cr...
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高三下学期化学《》真题及答案
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重铬酸钾法测定COD的实验中加入硫酸汞的作用是
催化剂
消除氯离子的干扰
调节pH值
氧化剂
1966年以前的甲醇合成工厂采用__工艺流程几乎都使用催化剂
锌铬
铜基
氧化铬
氧化锌
重铬酸钾K2Cr2O7是一种有毒且有致癌性的强氧化剂它被国际癌症研究机构划归为第一类致癌物质在实验室
+1
+6
-6
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甲醇合成催化剂主要分为两类类即系催化剂和系催化剂
重铬酸钾标准滴定溶液是氧化剂
水质化学需氧量的测定重铬酸盐法HJ828-2017代替GB11914-89测定 CODCr中重铬酸钾
还原剂
氧化剂
催化剂
掩蔽剂
快速COD测定仪为达到快速测定COD的目的改善反应条件即反应温度由143℃增至165℃消解时间由原标
加大水样流速
提高了酸度
加入复合催化剂
提高氧化剂重铬酸钾的浓度
重铬酸钾K2Cr2O7是一种有毒且有致癌性的强氧化剂它被国际癌症研究机构划归为第一类致癌物质在实验
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﹣6
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关于重铬酸盐测定化学需氧量以下说法正确的是
化学需氧量是指在一定条件下，经重铬酸钾氯处理时，水样中的溶解性物质所消耗的重铬酸盐相对应氯的质量浓度在酸性重铬酸钾条件下，水样中所有有机物全部被氯化
硫酸亚铁铵标准溶液应在每次使用前标定
Ag
2
SO
4
作滴定剂，消除Cl
-
干扰
HgSO
4
作催化剂
甲醇合成催化剂中铜基催化剂与锌铬催化剂比较正确的是
反应温度高
出塔甲醇含量高
副反应多
粗甲醇中杂质多
Oppenauer氧化反应常用的氧化剂为催化剂为
在用重铬酸钾法测定COD的试验中催化剂什么氧化剂是什么屏蔽剂是什么
主要用于医药工业有机合成中用作缩合剂化学试剂食用油脂处理的 催化剂等
甲醇
甲烷
甲醇钠
二氯甲烷
重铬酸钾基准物既可标定还原剂又可标定氧化剂
库仑法是重铬酸钾法测定水中COD时加入硫酸银的作用是
催化剂
氧化剂
还原剂
为什么说在酸性溶液中重铬酸钾是较强氧化剂而不说铬酸钾是较强的氧化剂
氨合成反应常用的铁系催化剂主要是以铁的为母体以还原铁为催化剂主要活性成分并掺加各种促进剂和载体的催化
常用的油脂抗氧化剂有
天然抗氧化剂
天然抗氧化剂、人工合成抗氧化剂和抗氧化剂增效剂
人工合成抗氧化剂
人工合成抗氧化剂和抗氧化剂增效剂
重铬酸钾氧化有机物时应加入Ag2SO4做催化剂
总铬测定时由于三价铬不与二苯碳酰二肼反应必须先将水样中的三价铬氧化成六价铬后测定采用的氧化剂为
高氯酸
重铬酸钾
过氧化氢
高锰酸钾
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1已知ab都是正数且a≠b求证a3+b3＞a2b+ab2 2已知abc都是正数求证≥abc．
ThebookingnotesoftheplayTheAgeofInnocence: Price:﹩10 BOOKING Therearefoureasywaystobookseatsforperformance: ﹣﹣inperson TheBoxOfficeisopenfromMondaytoSaturday10a.m.﹣8p.m. ﹣﹣bytelephone Ring01324976toreserveyourticketsortopaybycreditcardVisaMasterCardandAmexaccepted ﹣﹣bypost SimplycompletethebookingformandreturnittoGlobalTheatreBoxOffice. ﹣﹣online Completetheon﹣linebookingformatwww.Satan﹣fiedtheatre.com DISCOUNTS: Saver:﹩2offanyseatbookedanytimeinadvanceforperformancesfromMondayto Thursday.Saversareavailableforchildrenupto16yearsoldover60sandfull﹣timestudents. Supersaver:half﹣priceseatsareavailableforpeoplewithdisabilitiesandonecompanion.Itisadvisabletobookinadvance.Thereisamaximumofeightwheelchairspacesavailableandonewheelchairspacewillbehelduntilanhourbeforetheshow. Standby:bestavailableseatsareonsalefor﹩6fromonehourbeforetheperformanceforpeopleeligiblesuitableforSaverandSupersaverdiscountsandthirtyminutesbeforeforallothercustomers. GroupBookings:thereisatenpercentdiscountforpartiesoftwelveormore. School:schoolpartiesoftenormorecanbook﹩6standbyticketsinadvanceandwillgeteverytenthticketfree. Pleasenote:weareunabletoexchangeticketsorrefundmoneyunlessaperformanceiscanceledduetounforeseencircumstances. 1IfyouwanttobookaticketyouCANNOT. A.usetheInternet B.completeabookingformandpostittotheBoxOffice C.ringthebookingnumberandpayfortheticketsbycreditcard D.gototheBoxOfficeonSundays 2Accordingtothenoteswhocanget﹩2off? A.An18﹣year﹣oldteenager. B.A55﹣year﹣oldwoman. C.A20﹣year﹣oldfull﹣timecollegestudent D.ThepeoplewhobooktheticketsonFridays. 3Fromthepassagewecanknowallthefollowinginformationexceptthat. A.itisadvisabletobookticketsinadvance B.aschoolpartyof15studentsshouldpay﹩90forthestandbytickets C.theaudiencecan'trefundmoneyiftheperformanceisonshow D.agroupof13personscangeta10percentdiscount
不等式＜4的解集是．
观察下列一组数据 a1＝1 a2＝3+5 a3＝7+9+11 a4＝13+15+17+19 … 则a10从左到右第一个数是
假定英语课上老师要求同桌之河交换修改作文.请你修改你同桌写的以下作文.文中共有10处语亩错误毎句中杲多看两处毎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Λ并住其下面写岀该加的词 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毎处错误及其修改均仅限一词; 2.只允许修改10处.多者从11处起不计分. OnedayIaskedJennyoneofmyfriendwhethershewouldliketostudyEnglishwithme.YourideasoundedverygoodbecausewecanallimproveourEnglishJennysaid.''ThereforeIwon'tdothatbeforeyoumakeprogressinthecomeexaminationnextweek.'ThensheaskedifIwaswillingtomeetchallenge.HearingherwordsansweredwhatIwould.IusedtheInternetfilmsbooksoreverythingelsetoimprovemyEnglishskills.MuchtomyhappinessmadeitaweeklateandJennyagreedwithtostudytogetherwithme.
假定你是学生会__李华你校将举办主题为祖国颂的庆祝建国70周年文艺演出你将邀请你的英国朋友Joe观看这场演出.请你写封邮件向他介绍有关情况内容包括: 1.举办的时间和地点; 2.活动的目的; 3.活动的内容. 注意: 1.词数100左右; 2.可以适当增加细节以使行文连贯; 3.参考词汇:祖国颂OdetoOurMotherland;周年纪念日anniversary. DearJoe Yours LiHua
RogerFedererolderthanthepreviouslyoldestmanreturnedtoNo.1rankinginmen'stennisattheage36willbringa12﹣matchwinningstreak连胜totheBNPParibasOpenwhichstartsthisweekattheIndianWellsTennisGarden. Federerafive﹣timewinnerofthehard﹣courteventanda20﹣timeGrandSlamsingleschampiononTuesdaywasseededNo.1inafieldthathasbeengivenupbyinjuriestoseveralexcellentplayers.AmongthosemissingareworldNo.2RataclNadalhipinjuryStanWawrinkakneewholosttoFedererinthe2017finalDavidGoffineyeandAndyMurrayhipsurgery. Federerwhohasspent305weeksofhiscareeratthetoptheAssnofTennisProfessionalworldrankingsmustreachthesemifinalsatIndianWellstokeephisNo.Istatus.IfheexitssoonerthanthatNadalwouldregainthetopspot.Federerhasafirst﹣roundbye轮空andaseeminglyeasyprojectedroutetothequarterfinalswherehelikelywouldfaceNo.5seedDominicThiemofAustria. HewasaskedbyTheAssociatedPresswhatonefactorwasmostessentialtothiscareerrenaissance. MaybemypositivityyouknowFedererreplied.'Andmybeliefthat1couldgetbacktoNo.1and1couldgetbacktowinningways.Eveninthedifficultmoments1wasupbeatImustsay Hedidn'tdoitaloneofcourseIdidneedthefinalpushbymyteam.That'swhyIalwaystalkabouthowimportanttheyarebecausewithoutthemhonestlythere'snochanceIcouldhavedonethis.Andifthemajorityoronepersonwouldhavetoldme'LookIthinkyourdaysaredone'thenIthinkalsoitwouldbeadifferentsituationtodayhesaid.Buteverybodykindofbelievedinme. 1Whatcanweinferfromparagraph2? A.FederergaveupthematchonTuesdayduetotheinjury. B.ManyexcellentplayerstookpartinthematchincludingRafaelNadal. C.FedererwasluckyenoughseededNo.1onTuesday. D.StanWawrinkabeatFedererinthe2017final. 2WhydoesFedererhaveaseeminglyeasyprojectedroutetothequarterfinals? A.BecauseheisseededNo.l B.Becausehehasafirst﹣roundbye. C.Becausemanyexcellentplayersaremissing. D.Becauseheiswellenoughtobeatanyplayer. 3WhoismostlikelytobetheseednexttoFedereramongtheplayerswhocanplayintheBNPParibasOpen? A.RafaelNadal. B.MariaSharapova. C.NovakDjokovic. DDominicThiem. 4Whatisthebesttittleofthetext? A.RogerFedererseededNo.L B.RogerFederertobringa12﹣matchwinningstreak. C.RogerFedererbeateveryoneinthetournament. D.RogerFederertheoldestNo.1
Whilethousandsofcollegestudentsheadedforwarmclimatetoenjoysunandfunduringtheirweekofffromclassessevenlocalstudentshadotherplans TheNorthernEssexCommunityCollegeNECCstudentsandoneoftheirteachersspentpartoftheirspringbreakinNewYorkCity1helprepairanareadestroyedbythehurricane. IwantedtoseeformyselfwhathappenedsaidTerry.Icouldn'timagine2totalwhatitisliketoloseyourhomeandeverythingthatyouhadandthe3powereffectthehurricanehadonthosepeopleIwantedtodosomethingtounderstandtheirfeelingofhelplessness. ThegroupheadedintoBrooklyn'sRedHookdistrictwhich4strikehardbythehurricane.Theretheymetpeoplefromotherpartsofthecountrywhohadalsovolunteered5offerhelp. TogetherthosevolunteersandtheNECCstudentsworkedtoclearrubbishoutofathree﹣storybuilding.Theyputonprotectivesuitsandgloves6theyenteredthebuilding. Insidethebuildingthestudentssawnothingbutbrokenwallsanddoorsandpiecesofthebuildinglyingallover7place. Thestudentsreturnedtoschoolwithasenseof8achieveandtheyfelthappybecause9helpedpeopleinneed.Itwasremarkablehowacommunitylostsomuchandwasstillabletorecoverandthisleftthedeepestimpression10thestudents.
Ifyouwanttosavemoneyongroceriesfollowingwayswillhelpyoucut﹩100outofyourmonthlygrocerybillwithouttoomucheffort. 1Convenienceletsyousavetimeforotherthingsyouneedtogetdone.Pre﹣madeitemsmaysaveyourtimebuttheycostaprettypenny.Theseitemscomeintheformofpackageddinnersorpre﹣cutproduce.Insteadofthatplateofcutpineapplebuythewholefruitorvegetableforapartofthecost. Knowwhattobuyinbulk大批.Shoppingatwarehousestorescanbeagreatwaytosavemoneybutnoteveryitemisworthbuyinginbulk.2 SkipthemeatTheBureauofLaborStatisticsreportsthattheaveragecostofbeefis﹩4.13perpoundthisMarch.3Ifyouskipthebeeftwiceaweekyoucaninstantlycut﹩30to﹩40ifnotmoreoffyourgrocerybilleachmonth. Knowwhattobuyinseason.Fruitsandvegetablesareagreatadditiontoyourdailydietbuttheycanaddasignificantamounttoyourgrocerybillespeciallywhenyoubuyitemsoutofseason.4Ifyourfavoriteitemsaregettingreadytogooutofseasonconsiderbuyingalittleextraandfreezingthem. 5Howevertherearewaystostretchyourdollarfurtherwithouthurtingyourhabits. A.Storepre﹣madeitems. B.Skiptheprepareditems. C.Shoppingforgroceriescanbeanexpensiveattempt. D.Beefhasseenasignificantincreaseinpriceoverthepastfewyears. E.Thecostcanaddupquicklyifyou'reeatingbeefthreeorfourtimesperweek. F.Asproduceitemsgooutofseasonthebecomemoreexpensiveasthesupplydecreases. G.Certainitemsmakesensetobuyinlargequantitiesastheytypicallyhavealongershelflife.
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已知抛物线x2＝4y的焦点为F设Ax1y1Bx2y2是抛物线上的两个动点如满足y1+y2+2＝|AB|则∠AFB的最大值
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若z＝1+2i则＝
有5支彩笔除颜色外无差别颜色分别为红黄蓝绿紫．从这5支彩笔中任取2支不同颜色的彩笔则取出的2支彩笔中含有红色彩笔的概率为
若a＞b＞10＜c＜1则
下列说法错误的是
已知函数fx＝|2x|+|2x+3|﹣2．求不等式fx≤3的解集．
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IfellinlovewithYosemiteNationalParkthefirsttimeIsawitwhenIwas13.Myparentstookusthereforcamping.OnthewayoutIaskedthemtowaitwhileIranuptoE1Capitana1rockof3300feetstraightup.Itouchedthatgiantrockandknew2Iwantedtoclimbit.Thathasbeenmylife'spassion钟爱eversince﹣3therocksandmountainsofYosemite.I'velongmadeYosemitemy4. About15yearsagoIstartedseeingalotof5liketoiletpaperbeercansandemptyboxesaroundthearea.It's6mewhyvisitorsstartedrespectingtheplace7andtreatedsuchabeautifulhome﹣likeplacethisway. Itried8trash垃圾myselfbutthejobwastoobig.Iwould9anhourortwoonthejobonlytofindtheareatrashedalloveragainweekslater.FinallyIgotso10itthatIdecidedsomethinghadtochange. Asarock﹣climbingguideIknew11aboutorganizinganybigevent.Butin2014togetherwithsomeclimbersIsetadatefora12.Onthatdaymorethan300people13.Overthreedayswecollectedabout6000poundsoftrash.Itwasamazinghowmuchwewereableto14.Icouldn'tbelievethe15wemade﹣theparklookedclean! Eachyearvolunteerscomeforthecleanupfromeverywhere.In2016alone2945peoplepickedup42330poundsoftrashand16132milesofroadway. Ioftenhearpeople17abouttheirsurroundings.IfyouareoneofthemIwouldsaytheonlywaytochangethingsisby18ratherthancomplaining.Weneedtoteachby19.Youcan'tblameothers20youstartwithyourself. 1A.distant B.huge C.narrow D.loose 2A.immediately B.finally C.gradually D.recently 3A.imagining B.painting C.describing D.climbing 4A.garden B.home C.lab D.palace 5A.material B.resources C.waste D.goods 6A.beyond B.against C.over D.within 7A.more B.most C.less D.least 8A.throwingaway B.pickingup C.breakingdown D.diggingout 9A.kill B.save C.wait D.spend 10A.satisfiedwith B.delightedin C.tiredof D.usedto 11A.something B.anything C.everything D.nothing 12A.cleanup B.party C.picnic D.concert 13A.droppedout B.showedup C.lookedaround D.calledback 14A.demand B.receive C.accomplish D.overcome 15A.plan B.visit C.contact D.difference 16A.crossed B.measured C.covered D.designed 17A.talk B.complain C.argue D.quarrel 18A.doing B.thinking C.questioning D.watching 19A.method B.explanation C.example D.research 20A.although B.if C.when D.unless
假如你是李华衡水中学学生会__ChairmanoftheStudentUnion近日你校收到美国友好交流学校RogerManverzSchool学生会__John的邮件希望你校捐赠一批传统文化书籍供该校对此有兴趣的同学阅读请你代表学校给John回复一封邮件邮件中需要包含以下内容: 1.自我介绍; 2.捐赠图书的具体信息; 3.询问对方的收件地址和联系信息. 注意: 1.词数100左右; 2.可以适当增加细节以使行文连贯. DearJohn Yoursfaithfully LiHua
AlibabaCloudandtheHangzhoucitygovernmentannouncedthelaunchofETCityBrain2.0acloud﹣poweredandAl﹣drivenurbantraffic﹣managementsystemthataimstoincreasethecity'sefficiency. AfterovertwoyearsoftestinginAlibaba'shomebaseETCityBrainhasbecomethenewinfrastructure基础设施forHangzhouwithatotalcoverageof420squarekilometersinareaincludingover1300trafficlights.Over200trafficofficersareconnectedviamobilephonesenablingthemtoreceivereal﹣timealertsonanytraffic﹣relatedemergencies. Inversion2.0thesystemwilloptimizethecity'sfirefightingabilitiesbyprovidingkeyinformationtofirefighterssuchaswaterpressurethenumberandpositionoffirehydrants消防栓inagivenareathelocationofgaspipesandotherdetailstheyneedtoknow.Theinformationisinstantmakingtheentirefirefightingprocessfastersaferandmoreaccurate. CityBraingivesmeaningtodata.ByusingAIandadvancedalgorithms计算程序CityBrainisabletoanalyzealargeamountofdataandturnthemintousefulinformationinreal﹣timespeed. AsaresultofCityBrain'sabilitytopredicttrafficflowdetectaccidentsandprovideinstantfeedbackHangzhouhasdroppedfrom5thtothe57thonthelistofChina'smostcongestedcities.Hangzhouisprobablytheonlycitythatcantellyouhowmanycarsareonthestreetatanygiventime. InthecaseofmedicalemergenciesCityBrainisabletochangetrafficlightssoemergencyvehicleslikeambulancesandfiretruckscanheadtothescenewithoutinterruptionacceleratingtheirarrivaltimeby49%. Dr.WangJiantheheadofAlibaba'sTechnologySteeringCommitteewhoinventedthetermCityBrainsaidthesystemisdesignedtoempoweracitytoactquicklyanddirectly.Itismorethanjustabouttrafficmanagement.It'sreallyabouthowtomakecitymorelivableatatimeofshrinkingnaturalresourcesaroundtheglobe.ItisamatterofsustainabilitywhileusingaslittlenaturalresourcesaspossibleWangsaidThisisjustthebeginning. 1WhatbenefitwillETCityBrainbring? A.Lowercrimerates. B.Efficientgovernment. C.Lesstrafficcongestion. D.Improvedmedicalcare. 2WhichofthefollowingfunctionsofthecityBrainisNOTmentionedinthetext? A.Predictingtrafficflow. B.Givingquickfeedback. C.Changingtrafficlights. D.Handlingtrafficaccidents. 3Whichofthefollowingbestexplainsoptimizeinparagraph3? A.Better. B.Practise. C.Operate. D.Emphasize. 4Whatcanweconcludefromthelastparagraph? A.ETCityBrain2.0isafullydevelopedversion. B.Alibabatargetsenvironmentally﹣friendlydevelopment. C.Thegovernmentisdevotedtoimprovingthesystem. D.Thesystemcansolvetheproblemoflackofresources.
IfyouliveinWashingtonD.C.orRedwoodCalif.youmayhaveglimpsedasmallboxyrobotrollingalongalocalsidewalkmindingitsownbusinessbutattractingtheattentionofmanyacuriousonlooker. TherobotswhichlooklikeelectricricecookerswithwheelswerepartofapilotprogramlastyearbyStarshipTechnologiesfocusedondeliveringmealsfromlocalrestaurantsindozensofcitiesaroundtheworld. Thisweekthecompanyrevealedplanstobroadenit'sdeliveryservicebeyondfoodtoincludepackagesamovethatmadeittheworld'sfirstrobotpackagedeliveryservice.ThepackagedeliveryserviceisonlyavailableinsomecitiesintheUS. Thewheeledrobotshaveatopspeedof4mphandandcandetectbarriersfromasfaras30feetaway.TherobotcanoperatethroughjustaboutanythingsaysNickHandrickheadofoperationsforStarship'sD.C.officeIfyouhavesomethinginthewayit'sabletoclimbit.BygivingcustomerscontrolofwhendeliveriesoccurStarshipTechnologiesispromotingitsserviceasawaytocombatpackagetheft. Tosignupfortheservicewhichcostsalittlemorethan﹩10permonthcustomersneedtodownloadthecompany'sapp.CustomersthencreateaStarshipDeliveryAddressauniqueaddressinsideaStarshipfacilityinsteadofahomeaddresswheretheycanhavepackagessentfromplacessuchasAmazon.com. OnceapackageisdeliveredtotheStarshipaddresscustomersreceiveatextnoticethatallowsthemtoscheduleahomedeliveryviarobot.Therobotsareopenedbycustomerswithamobilephonecode代码. 1WhatdoweknowaboutStarshipTechnologiescompany? A.PackagesaredeliveredbyitsrobotsallroundAmerica. B.Itsrobotshavetakenonpackagedeliveryforalongtime. C.Itisthefirsttoproviderobotpackagedeliveryservice. D.Itsdeliveryserviceisthebestofallintheworld. 2WhatdoestheunderlinedwordcombatinParagraph4probablymean? A.Delay B.Prevent C.Report D.Discover 3Whatcanwelearnaboutrobotpackagedeliveryservice? A.Customerscan'topentherobotswithoutamobilephonecode. B.StarshipDeliveryAddressisthecustomer'shomeaddress. C.Customershavetopayalittlemorethan﹩10eachtime. D.Robotsthemselveshavecontroloverwhentodeliverpackages. 4Whatmaybethebesttitleforthepassage? A.RobotDeliveryServiceIsTakingOff B.HumansAreBeingReplacedbyRobots C.EverythingCanBeDonebyRobots D.PackagesCanBeDeliveredbyRobots
ManylanguagesaredisappearingandlanguagessuchasEnglishSpanishandChineseareincreasinglytakingover.YetMaoripromisestohavearosyfuturegiventhatNewZealandersareshowinggreatenthusiasmforspeakingthislocallanguage. AMaorirenaissance复兴blossomedinthe1970saslanguageactivistschampionedtheircauseandMaorifoughtforgreaterpoliticalpower.Butuntil2013just3.7percentofNewZealandersspokethelanguagefluentlyandmanypredicteditwouldsoondieout.NowNewZealand'sgovernmentiserasingprejudiceandstrugglingtoincreasethepercentofpopulationwhocanspeakbasicMaoriby2040to20.PrimeMinisterJacindaArdernsaidlastmonththathernewborndaughterwouldlearnbothMaoriandEnglish.It'sanofficiallanguagesowhyshouldwedismissitsuniversalavailabilityanditsmuchmorecommonuse?saidMs.Ardernaddingthatshealsoplannedtostudythelanguage.Grassrootsarealsospreadingitbywordofmouth.Answeringthephonewiththegreetingkiaorahelloorendinganemailwithngamihi'thankshasbecomeafashion.MaoriisgraduallybecomingpartofNewZealand's mainstreampopularculture. AjitKumarSamahafamousprofessorinAucklandUniversitypublishedabook﹣Contagious:whyMaoricatchesonwhereheintroducesreaderstothepopularityofMaoriandexpresseshisgreatanxietyforthelackofteacherswhohavethecompetencetoteachtheMaorilanguage. Peoplearenotonthesamewavelengthhowever.SuggestionsonofficiallyreplacingEnglish﹣languageplacenameswithtraditionalMaorioneshavebeenrejected.SowhenapolicecarwasdesignedusingMaoriitwascondemnedbysomeasridiculousbecauseofthehigherMaoriratesofarrestandimprisonment. 1Howdoestheauthorintroducethetopic? A.Byprovidingusefuldata. B.Bymakingacomparison. C.Byapplyingfamoussayings. D.Byofferinggoodtips. 2Whatdowelearnfromthesecondparagraph? A.TheMaorilanguagethreatenstheriseofEnglish. B.There's11be20%fluentMaorispeakersby2040. C.ArdernisopenlysupportiveoflearningMaori. D.PeoplewithdrawfromtheactofspeakingMaori. 3WhatcanweknowaboutAjitKumarSamah? A.HepopularizestheuseofMaori. B.HeseesMaoriasanunofficiallanguage. C.HerejectsthereplacementofEnglishwithMaori. D.HeadvocatestrainingcompetentMaoriteachers. 4Whatcanbeasuitabletitleforthetext? A.TheBrought﹣to﹣lifeMaoriLanguage B.ToSpeakorNottoSpeakMaori C.HowtoHaveGreatFluencyinMaori D.TheEvolutionoftheMaoriLanguage
已知椭圆E+＝1a＞b＞0的半焦距为c原点O到经过两点c00b的直线的距离为c． Ⅰ求椭圆E的离心率 Ⅱ如图AB是圆Mx+22+y﹣12＝的一条直径若椭圆E经过AB两点求椭圆E的方程．
I'msuremanyofyouarefamiliarwiththeNewYear'sresolution决心﹣﹣‘get1'AfteraChristmasofstaving2.watchingtelevisionandeatingfartoomuchchocolateIdecidedenoughwasenough.Januarywasgoingtobe3.Januarywasgoingtobethestartofthenew.healthyme﹣lesschocolate.more4anall﹣roundhealthierlifestyle.ButhowwasIgoingtodothis?AsI5theInternetlookingforinspirationIrealizedjusthow6Iknewaboutwaystogetfit.7exerciseIhadalwaysthoughtyoueitherplayedateamsportlike8orwenttothegym.AndwiththearrivalofJanuarysnowplayingfootballoutsidedidn'tseemlikediebestoption.andasIhaveadeep﹣rootedterrorof9runningmachinesthegymwasn'tgoingtoworkouteitherPlusEveneverquiteunderstoodtheconceptof10toruninsidewhenyoucouldrunoutsideforfree. 11IknewthatIneededtoresearchmyoptionsfurther.ThefirstthingIfoundwastheworldofYouTubeexercisevideos.Therearevideosforjustabouteverything.The12thingaboutYouTubevideosisthattheyarefreetheyare13youcandothemwheneveryouwantandyoudon'thaveto14yournicewarmhousetodothem.But15youdothemwithafriendit'stoughto16yourselftokeepgoingandwithoutaninstructortherewithyouit'ssometimeshardtoknowifyou'redoingthemove17. Ithenresearchedlocalfitnessclassesandfoundmysmalltowntobeabsolutelyswimmingwith18!Iquicklysigneduptotheoverallsportsclubhadalookattheweeklytimetableand19totrythemallout.SofarIhavetriedoutmostofthem.My20onesarebyfarthedance﹣basedonesthattakeplacetomusicbecauseitmakesexercisesomuchmorefun! 1A.rich B.fit C.busy D.ready 2A.alone B.abroad C.inactive D.positive 3A.hard B.similar C.relaxing D.different 4A.workouts B.foods C.fun D.sleep 5A.looked B.surfed C.checked D.enjoyed 6A.few B.much C.little D.many 7A.Incaseof B.Inadditionto C.Intermsof D.Inspiteof 8A.tennis B.basketball C.badminton D.football 9A.gettingoff B.takingoff C.givingoff D.fallingoff 10A.paying B.planning C.practicing D.playing 11A.Therefore B.However C.Besides D.Otherwise 12A.serious B.confusing C.wonderful D.amusing 13A.cheap B.flexible C.useful D.safe 14A.clean B.leave C.build D.buy 15A.if B.though C.since D.unless 16A.force B.encourage C.stimulate D.motivate 17A.smartly B.quickly C.correctly D.beautifully 18A.opportunity B.danger C.pressure D.patience 19A.agreed B.decided C.believed D.advised 20A.favorite B.creative C.ordinary D.regular
已知A31B﹣40P是椭圆上的一点则PA+PB的最大值为．
IfeltbutterfliesinmystomachwhenIstartedcalligraphyclasstenyearsago.IwonderedwhatIwasdoingthere.AtthatmomentIcouldn'thaveknownthatI'djustmadeoneofthebest1chooseofmylife. Isatdownandlistenedtotheteacherintroducingthetoolsofthecraft.Then2wasthefirsttimeformethatIhadtriedmyhand.Itookupthebrushusingthecorrectgesture3dipitintheinkandcarefullywroteone4Chinese. Over5pastfiveyearsIhavelearnedtomakeversionsofwell﹣knownpoems.Calligraphyseemedlikeabridge6connectedmetoauthorsfromcenturiespast.Stroke笔画bystrokewordbywordIcouldfeeltheiremotionscherishedmyownpeaceandlearned7appreciatemydailylife. Nowcalligraphyisnotjustahobby8awaytoremovemyselffromtheworriesoflife.RollingoutthepaperIcanwriteforawholeday.Calligraphy9ablemetobalancemybusyscheduleandlive10peace.
已知直线l的参数方程为t为参数．在平面直角坐标系xOy中P12以坐标原点O为极点x轴的正半轴为极轴建立极坐标系已知曲线M的极坐标方程为ρ＝4cosθ直线l与曲线M交于AB两点． 1求曲线M的直角坐标方程 2求|PA|・|PB|的值．
ChinaTrainGuide QuickGuideonChinaTrainTravel Ifyou'relookingforanaffordableandcomfortablewaytogetaroundChinatraintravelisthewaytogo.Gettingtraininformationandcheaptrainticketshasneverbeeneasier.OnlinetrainticketbookingmakesiteasyfortravelerstolookthroughChina'straintimetablecomparetrainfaresandlookforticketavailability.Onceyou'vefoundasuitabletrainyoucanbookonlineandpickyourticketsupatthetrainstationorgetthemdeliveredtoyourhomeorhotel.Trainticketscanbebookedonlineaminimumof35minutesandamaximumof60daysbeforedeparture. Howtochoosetraintypes Whenyou'rebuyingChinatrainticketsonlineyou'llnoticethatthejourneydurationdiffersdependingonwhichtypeoftrainyouchoose.ChinatraintypescanberecognizedbytheirlettercodesGDandCtrainsarehigh﹣speedtrainswhileZTandKareslowerorovernighttrains.China'shigh﹣speedtrainsrunbetweenChineseprovincialcapitalsandfirst﹣tierChinesecities.Gtrainshigh﹣speedtrainsstandingforgāotiěareChina'sbullettrains﹣thefastesttrainswithamaximumspeedof400km/h.Ticketsforthesetrainsarethemostexpensive. Howtobuytraintickets UnlessyoucanreadChinesethereareonlytwowaystomaketrainreservationsinChina: ﹣Onlinetrainticketbookingwithatravelagencyupto60daysbeforedeparture. ﹣Atthetrainstation/localticketagencywithyourpassportupto58daysbeforedeparture. Howtoreadtraintickets WhenreadingyourtrainticketpleasetakenoteoftheChinesecharactersandPinyinprintednexttoyourdeparture/arrivalcity.DirectionsNorthSouthEastandWestappearinPinyinBeiNanDongandXinotEnglish.Pleasemakesureyouaregoingtothecorrecttrainstation. 1Whatcanwelearnfromthefirstparagraph? A.It'sdifficulttogettraininformationinChina. B.Youcangetonthetrainwithoutticketsafterbookingonline. C.TravelingbytraininChinaisnotveryexpensive. D.Trainticketsonlineareavailableatanytimewithin60daysbeforeyouleave. 2IfMr.SmithneedstotravelfromJinantoBeijingforsomethingurgenthe'dbettertake. A.Gtrains B.Ztrains C.Dtrains D.Overnighttrains 3Whoaretheintendedreadersofthepassage? A.Nativetourists. B.Travelagencies. C.Businessmen. D.Foreigntravelers.
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