www.TopwayEnglish.comwww.TopwayEnglish.com10篇真题记400词真题对备考四级的考生来说袁最具权威性遥编者从历年真题中精选出10篇含高频词汇最为丰富的文章袁以帮助考生高效复习四级词汇袁做到事半功倍遥Passage1ABriefHistoryofBlackBoxesYouneverseethem,butthey蒺rewithyoueverytimeyoufly.Theyrecordwhereyou蒺regoing,howfastyou蒺retravelingandwhethereverythingonyourairplaneisfunctioningnormally.Theirabilitytowithstandalmostanydisastermakesthemseemlikesomethingoutofacomicbook.Theyareknownastheblackbox.Whenplanesfallfromthesky,asaYemeniairlinerdidonitswaytotheComorosIslandsintheIndianOceanJune30,2009,theblackboxisthebestbetforidentifyingwhatwentwrong.SowhenaFrenchsubmarine(潜水艇)detectedthedevice蒺shomingsignalfivedayslater,thediscoverymarkedahugesteptowarddeterminingthecauseofatragedyinwhich152passengerswerekilled.In1958,AustralianscientistDavidWarrendevelopedaflight鄄memoryrecorderthatwouldtrackbasicinformationlikealtitudeanddirection.Thatwasthefirstmodelforablackbox,whichbecamearequirementonallU.S.commercialflightsby1960.Earlymodelsoftenfailedtowithstandcrashes,however,soin1965thedevicewascompletelyredesignedandmovedtotherearoftheplane要thearealeastsubjecttoimpact要fromitsoriginalpositioninthelandingwells(起落架舱).Thatsameyear,theFederalAviationAuthorityrequiredthattheboxes,whichwereneveractuallyblack,bepaintedorangeoryellowtoaidvisibility.Modernairplaneshavetwoblackboxes:avoicerecorder,whichtrackspilots蒺conversations,andaflight鄄datarecorder,whichmonitorsfuellevels,enginenoisesandotheroperatingfunctionsthathelpinvestigatorsreconstructtheaircraft蒺sfinalmoments.Placedinaninsulated(隔绝的)caseandsurroundedbyquarter鄄inch鄄thickpanelsofstainlesssteel,theboxescanwithstandmassiveforceandtemperaturesupto2,000毅F.Whensubmerged,they蒺realsoabletoemitsignalsfromdepthsof20,000ft.ExpertsbelievetheboxesfromAirFranceFlight447,whichcrashednearBrazilonJune1,2009,areinwaternearlythatdeep,butstatisticssaythey蒺restilllikelytoturnup.Intheapproximately20deep鄄seacrashesoverthepast30years,onlyone...
