Many people believe the glare from snow causes snowblindnenss. Yet, dark glasses or not , they find themselves suffering from headaches and watering eyes,and even snowblindness,wh
树图思维导图提供 2017年12月英语四级阅读练习:仔细阅读(16) 在线思维导图免费制作,点击“编辑”按钮,可对 2017年12月英语四级阅读练习:仔细阅读(16) 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:8615dc31a4f7731767deb38429253e47
2017年12月英语四级阅读练习:仔细阅读(16)思维导图模板大纲
Manypeoplebelievetheglarefromsnowcausessnowblindnenss.Yet,darkglassesornot,theyfindthemselvessufferingfromheadachesandwateringeyes,andevensnowblindness,whenexposedtoseveralhoursof"snowlight".
TheUnitedStatesArmyhasnowdeterminedthatglarefromsnowdoesnotcausesnowblindnessintroopsinasnow-coveredcountry.Rather,aman'seyesfrequentlyfindnothingtofoucsoninabroadexpanseofbarrensnow-coveredterrain.Sohisgazecontinuallyshiftsandjumpsbackandforthovertheentirelandscapeinsearchoftsomethingtolookat.Findingnothing,hourafterhour,theeyesneversotpsearchingandtheeyeballsbecomesoreandtheeyemusclesache.Natureoffsetsthisirritationbyproducingmoreandfluidwhichcoverstheeyeball.Thefluidcoverstheeyeballinincreasingquantityuntilvisionblurs,thenisobsured,andtheresultistotal,eventhoughtemporary,snowblindness.
ExperimentsledtheArmytoasimplemethodofovercomingthisproblem.Scoutsaheadofamainbodyoftroopsaretrainedtoshakesnowfromevergreenbushes,creatingadottedlineastheycrosscompletelysnow-coveredlandscape,Eventhescoutsthemselvesthrowlightweight,darkcoloredobjectsaheadonwhichtheytoocanfocus.Themenfollowingcanthenseesomething.Theirgazeisarrested.Theireyesfocusonabushandhavingfoundsomethingtosee,stopscouringthesnow-blanketedlanscape.Byfocusingtheirattentionononeobjectatatime,themencancrossthesnowwithoutbecominghopelesslysnowblindorlost.Inthiswaytheproblemofcrossingasolidwhiteterrainisovercome.
a.indispensible
b.useful
c.ineffective
d.available
a.clearthevision
b.remedysnowblindness
c.easetheirritation
d.loosenthemuscles
a.concentratingtothesolidwhiteterrain
b.searchingforsomethingtolookatinsnow-coveredterrain
c.providingtheeyeswithsomethingtofoucson
d.coveringtheeyeballswithfluid
a.bivethemenbehindsomethingtosee
b.beautifythelandscape
c.warmthemselvesinthecold
d.preventthemenbehindfromlosingtheirway
a.snowblindnessandhowtoovercomeit
b.natrue'scureforsnowblindness
c.soldiersinthesnow
d.snowvision
adcbc
相关文章
四级阅读:奥巴马看射杀拉登表情冷淡眼神空洞PresidentObamawaswatchingonaTVscreenasacommandogunneddownOsamaBinLaden.Viaavideocamerafixedtothehelmetofa...
TheNewGenderGapWhentheleadersoftheClassof2003assembleinLawrenceHigh'sfluorescent-lit1meetingrooms,mostoftheboysarenowheretobeseen.Theseniorclass...
HowLongCouldYouGoWithoutComplainingBaseballfansaregearingupfortheWorldSeries,butweallknowwhat'stherealnationalpastime:complaining.Couldyougowithou...
Theriseofmultinationalcorporations(跨国公司),globalmarketing,newcommunicationstechnologies,andshrinkingculturaldifferenceshaveledtoanunparalleledincreaseingl...
Anewanalysisoffederalmoneythatpublicschoolsreceiveforlow-incomestudentsshowsthatarecordnumberofthenation’sschooldistrictswillreceivelessinthecomingac...
FederalExpressisacompanythatspecializesinrapidovernightdeliveryofhigh-prioritypackages.Thefirstcompanyofitstype,FederalExpresswasfoundedbytheyouthfulFre...
By1970,accordingtoaWorldWildlifeFundreport,onlyabout4,500tigerssurvivedthroughouttheworld-halfoftheminIndia.Mr.Foresters,whofollowedandcountedtigerfoot...
AremarkablevarietyofinsectsliveinthisplanetMorespeciesofinsectsexistthanallotheranimalspeciestogether.Insectshavesurvivedonearthformorethan300million...
TheEarthcomprisesthreeprincipallayers:thedense,iron-richcore,themantlemadeofsilicate(硅酸盐)thataresemi-moltenatdepth,andthethin,solid-surfacecrustThere...