WecanvisityourcompanyonMondayorTuesday,ourplansarefairly__________.
Ifyoudonotfindtherequiredinformationusingthetipsfromtheprevioussection,thenyouneedtoconsultanonlineservicetofindthepieceofinformationyouwerelookingfor.Threedifferenttypesofserviceshavebeenestablishedovertheyears:crawlers,directoriesandmetasearchengines.Thefirstcrawlerwascreatedbackin1993.ItwascalledtheWorldWideWorm.Itcrawledfromonesitetothenextandindexedallpagesbysavingthecontentofthewebpagesintoahugedatabase.Crawlersorspidersvisitawebpage,readit,andthenfollowlinkstootherpageswithinthesiteandevenfollowlinkstoothersites.Webcrawlersreturntoeachsiteonaregularbasis,suchaseverymonthortwo,tolookforchanges.Everythingacrawlerfindsgoesintoadatabase,whichpeopleareabletoquery.TheadvantageofthewebcrawlersisthattheyhaveanextensivedatabasewithalmostthecompleteInternetindexedinit.Thedisadvantageisthatyougetthousandsofwebpagesasaresponseforalmostanyrequest.Webdirectoriesworkalittledifferently.Firstofalltheycontainastructuredtreeofinformation.Allinformationenteredintothistreeiseitherenteredbythewebmasterwhowantstoannouncehisnewwebpageorbythedirectorymaintainerwholooksatthewebpagessubmitted.ThedirectorieswherewebmasterscansubmitboththeURL(UniformResourceLocator)andthedescriptionnormallycontainmoremisleadinginformation.Gettingintomostwebdirectoriesisacombinationofluckandquality.Althoughanyoneisabletosubmitawebpage,thereisnoguaranteethatacertainpagewillbeincluded.Somedirectorieschargeforsubmission,whichisbasicallyarip-off.Somecrawlersmaintainanassociateddirectory.Ifyoursiteisinthedirectory,therankingofyourwebsitenormallywillbehigher,asitisalreadypre-classified.Manydirectoriesworkwithcrawlerstogether,inordertodeliverresults,whennothingcanbefoundinthedirectory.MetasearchenginesdonothaveadatabasewithURLsanddescriptions.Insteadtheyhaveadatabaseofsearchengines.Ifyouenteryourkeywordsintoametasearchengineitwillsendoutrequeststoallthedirectoriesandcrawlersithasstoredinitsdatabase.ThemetasearchengineswithamoresophisticatedapplicationinthebackgroundareabletodetectdoubleURLswhichcomebackfromthevarioussearchenginesandpresentonlyasingleURLtothecustomer.
34.Crawlerisakindof__________.
A.wormB.searchengineC.serviceD.directory
35.ThedisadvantageofCrawleristhatit__________.
A.providesacompletedatabase
B.takestoomuchtimetofindtheneededinformation
C.providestoomuchuselessinformation
D.givesresponsetoeveryquest
36.Whocaninputinformationtothewebdirectories?
A.Onlywebmasters.
B.Bothdirectorymaintainersandwebmasters.
C.Anyonewhowantstoannounceawebpage.
D.Anyonewhohasfoundanewwebpage.
ProfessorTate__________abouthim.
CMOS由锂电池供电，以便在关机后__不丢失。如果CMOS参数经常丢失，就有可能是__+。
无固定调车机利用本务机调车作业的中间站，调车作业时，由（）负责将机车控制器送往机车，安放适当牢固位置，作业完了及时取回。
万用表一般可进行四种测量，它们分别是直流电压档、电流档、交流电压档、（）。
货物（）是货运全过程的一种运送单证，还是编制记录、备查或处理事故赔偿的凭据。
光缆线路的维护工作一般可分为__、__。
环境标准按内容主要有__________标准和__________标准
车体下两侧有下垂的门挡木、门挡簧或其它妨碍上鞋的突出物件，使用（）制动应特别注意。
推进车辆运行时，（）应站在易于瞭望确认前方进路又能使司机看见其信号显示的位置。
十、五、三车距离信号是表示()距被连挂车辆的距离。
在无联锁的线路上接发列车时，应将进路上（）加锁。进路上的分动外锁闭道岔无论对向或顺向，均应对（）加锁。