2015年12月英语四级阅读真题练习及答案1思维导图
It is hard to track the blue whale, the ocean’s largest creature, which has almost been killed off by commercial whaling and is now listed as an endangered species. Attaching rad
树图思维导图提供 2015年12月英语四级阅读真题练习及答案1 在线思维导图免费制作，点击“编辑”按钮，可对 2015年12月英语四级阅读真题练习及答案1 进行在线思维导图编辑，本思维导图属于思维导图模板主题，文件编号是：b93875983f4b42d6ca2bcab34ea4c9b1
思维导图大纲
2015年12月英语四级阅读真题练习及答案1思维导图模板大纲
Itishardtotrackthebluewhale,theocean’slargestcreature,whichhasalmostbeenkilledoffbycommercialwhalingandisnowlistedasanendangeredspecies.Attachingradiodevicestoitisdifficult,andvisualsightingsaretoounreliabletogiverealinsightintoitsbehavior.
Sobiologistsweredelightedearlythisyearwhen,withthehelpoftheNavy,theywereabletotrackaparticularbluewhalefor43days,monitoringitssounds.ThiswaspossiblebecauseoftheNavy’sformerlytop-secretsystemofunderwaterlisteningdevicesspanningtheoceans.
TrackingwhalesisbutoneexampleofanexcitingnewworldjustopeningtocivilianscientistsafterthecoldwarastheNavystartstoshareandpartlyuncoveritsglobalnetworkofunderwaterlisteningsystembuiltoverthedecadestotracktheshipsofpotentialenemies.
Earthscientistsannouncedatanewsconferencerecentlythattheyhadusedthesystemforcloselymonitoringadeep-seavolcaniceruption(爆发)forthefirsttimeandthattheyplansimilarstudies.
Otherscientistshaveproposedtousethenetworkfortrackingoceancurrentsandmeasuringchangesinoceanandglobaltemperatures.
Thespeedofsoundinwaterisroughlyonemileasecond—slowerthanthroughlandbutfasterthanthroughair.Whatismostimportant,differentlayersofoceanwatercanactaschannelsforsounds,focusingtheminthesamewayastethoscope(听诊器)doeswhenitcarriesfaintnoisesfromapatient’schesttoadoctor’sear.Thisfocusingisthemainreasonthatevenrelativelyweaksoundsintheocean,especiallylow-frequencyones,canoftentravelthousandsofmiles.
1.Thepassageischieflyabout________.
A)anefforttoprotectanendangeredmarinespecies
B)thecivilianuseofamilitarydetectionsystem
C)theexposureofaU.S.Navytop-secretweapon
D)anewwaytolookintothebehaviorofbluewhales
2.Theunderwaterlisteningsystemwasoriginallydesigned________.
A)totraceandlocateenemyvessels
B)tomonitordeep-seavolcaniceruptions
C)tostudythemovementofoceancurrents
D)toreplacetheglobalradiocommunicationsnetwork
3.Thedeep-sealisteningsystemmakesuseof________.
A)thesophisticatedtechnologyoffocusingsoundsunderwater
B)thecapabilityofsoundtotravelathighspeed
C)theuniquepropertyoflayersofoceanwaterintransmittingsound
D)low-frequencysoundstravelingacrossdifferentlayersofwater
4.Itcanbeinferredfromthepassagethat________.
A)newradiodevicesshouldbedevelopedfortrackingtheendangeredbluewhales
B)bluewhalesarenolongerendangeredwiththeuseofthenewlisteningsystem
C)opinionsdifferastowhethercivilianscientistsshouldbeallowedtousemilitarytechnology
D)militarytechnologyhasgreatpotentialincivilianuse
5.WhichofthefollowingistrueabouttheU.S.Navyunderwaterlisteningnetwork?
A)Itisnowpartlyaccessibletocivilianscientists.
B)Ithasbeenreplacedbyamoreadvancedsystem.
C)Itbecameuselesstothemilitaryafterthecoldwar.
D)Itisindispensableinprotectingendangeredspecies
参考答案
1.B2.A3.C4.D5.A
沪公网安备 31011502019485号
上海工商