首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Many people believe the glare from snow causes snow blindness. Yet, dark glasses or not they find themselves suffering from head
Many people believe the glare from snow causes snow blindness. Yet, dark glasses or not they find themselves suffering from head
admin
2015-01-09
30
问题
Many people believe the glare from snow causes snow blindness. Yet, dark glasses or not they find themselves suffering from headaches and watering eyes, and even snowblindness, when exposed to several hours of "snow light".
The United States Army has now determined that the glare from snow does not cause snow-blindness in troops in a snow-covered country. Rather, a man’s eyes frequently find nothing to focus on in a broad expanse of a snow-covered area. So his gaze continually shifts and jumps back and forth over the entire landscape in search of something to look at. Finding nothing, hour after hour, the eyes never stop searching and the eyeballs become sore and the eye muscle aches. Nature balances this annoyance by producing more and more liquid which covers the eyeballs. The liquid covers the eyeballs in increasing quantity until vision blurs . And the result is total, even though temporary, snowblindness.
Experiments led the Army to a simple method of overcoming this problem. Scouts ahead of a main body of troops are trained to shake snow from evergreen bushes, creating a dotted line as they cross completely snow-covered landscape. Even the scouts themselves throw lightweight, dark-colored objects ahead on which they too can focus. The men following can then see something. Their gaze is arrested. Their eyes focus on a bush and having found something to see, stop searching through the snow-blanketed landscape. By focusing their attention on one object at a time, the man can cross the snow without becoming hopelessly snowblind or lost. In this way the problem of crossing a solid white area is overcome.
Snow-blindness may be avoided by_____.
选项
A、concentration on the solid white area
B、providing the eyes with something to focus on
C、searching for something to look at in snow-covered areas
D、covering the eyeballs with liquid
答案
B
解析
从第三段最后两句可知B为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/qpQO777K
0
考博英语
相关试题推荐
Hereisagreatironyof21st-centuryglobalpublichealth;Whilemanyhundredsofmillionsofpeoplelackadequatefoodasare
Havingafewtoomanydrinkscanmeanmorethanjustablackoutorabadhangover.Peoplewhoengageinbingedrinkingarecourt
2009wastheworstyearfortherecordlabelsinadecade.【C1】______was2008,andbeforethat2007and2006.Infact,industryr
Johnhasreceivedofferlettersfromthreecompanies,buthewantsto______hisoptionsopen,ashehasn’tdecidedwhatkindofj
Theprincipleofthesocialcharacteroftheschoolasthebasicfactorinthemoraleducationgivenmaybealsoappliedtothe
Therearsectionofthebraindoesnotcontractwithage,andonecancontinuelivingwithoutintellectualoremotionalfacultie
PsychologistAlfredAdlersuggestedthattheprimarygoalofthepsyche(精神)wassuperiority.Although【1】hebelievedthatindividu
Cultureisactivityofthought,andreceptivenesstobeautyandhumanefeeling.【1】ofinformationhavenothingtodowithit.Am
Everygeologistisfamiliarwiththeerosioncycle.Nosoonerhasanareaoflandbeenraisedalivesea-levelthanitbecomess
Simon’sletterwasinsuchacasualscrawl,andinsuchpaleink,thatitwas____
随机试题
依照最高人民法院的司法解释,当事人在离婚时请求返还按照习俗给付的彩礼,人民法院应当予以支持的情形有()
在刑事诉讼中,鉴定人应当具备的条件是
哮证发作期的病因病理关键是(题)(1991年第42题)
()是表达招标采购工作中各项工作的开展顺序、开始和完成时间以及相互衔接关系的计划。
东风厂2008年3月31日科目余额表如下:请根据上述资料回答以下各题:“无形资产减值准备”账户属于资产类账户,其余额一般应当在()。
关于股份支付的计量,下列说法中正确的有()。
________是指相同时值的强拍与弱拍有规律地循环出现。
人出生头2—3年心理发展成就的集中表现是()。
在关系数据模型中,二维表的行称为元组,二维表的列称为【】。
AgricultureFewpeoplethinkofSaudiArabiaasafarmcountry,Butagriculturalproductionreached1.5billionlastyearan
最新回复
(
0
)