首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
金融经济
Many people believe the glare from snow causes snow-blindness. Yet, dark glas...
Many people believe the glare from snow causes snow-blindness. Yet, dark glas...
admin
2020-12-24
56
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 snow-blindness, when exposed to several hours of "snow light".
The United States Army has now determined that 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 barren snow-covered terrain. 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 muscles ache. Nature offsets this irritation by producing more and fluid which covers the eyeball. The fluid
covers the eyeball in increasing quantity until vision blurs,then is observed, and the result is total, even though temporary, snow-blindness.
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 scouring the snow-blanketed landscape. By focusing their attention on one object at a time, the men can cross the snow without becoming hopelessly snow-blind or lost. In this way the problem of crossing a solid white terrain is overcome.
Snow-blindness may be avoided by_________.
选项
A. concentrating to the solid white terrain
B. searching for something to look at in snow-covered terrain
C. providing the eyes with something to focus on
D. covering the eyeballs with fluid
答案
C
解析
根据第二段可知,雪盲症的发生最根本的原因是茫茫雪原上没有除了白色以外的颜色 可以看到.因而眼睛疲劳,因此提供可以聚焦的物体是根本预防办法,故选C。
转载请注明原文地址:https://ti.zuoweng.com/ti/Ixk8KKKQ
相关试题推荐
TherearemuchmanymorepeoplethanIexpected.A.ThereB.muchC.manyD.than
Imetseveralpeoplethere,twoof______beingforeigners.A.whomB.themC.wh
Webelievethat_________recentchangesinstatelaws,themajorityvotestan...
Manypeoplebelievetheglarefromsnowcausessnow-blindness.Yet,darkglas...
Themanagementbelievesthat__________allofthedamagedgoodswillcostmor...
Accordingtonewsreports,personal__________ofgunsintheUSAcausesalot...
Agoodadvertisementoftenuseswords__________peopleattachpositivemeanings.A
Socialchangeislesslikelytooccurinasocietywherepeoplearequitesim...
根据下列内容,回答201-205题。 Inthelate1960s,manypeopleinNorthAmericaturnedth...
Sincepeoplearefondofhumor,itisaswelcomeinconversationas__________...
随机试题
市场需求不太明确不确定风险高而且目前尚看不到什么明显的利润商品的天折率很高。这样
关于质量方针,错误的说法是哪项 A.是由组织的最高管理者正式发布的该组织总的质
根据发展常模得出的儿童智力评定结果称为()。单选
下列关于参与各方项目管理的目标的说法,正确的有()。
具有医院药学工作特色的职业道德要求是
某研究者拟采用多中心、随机、双盲临床试验评价补肾活血颗粒改善帕金森病患者运动功能
35kV及以下输电线路一般不采取全线路架设避雷线措施的原因是()。 A.感应
在国际贸易中,对于计算商品重量时如何计算商品包装的重量,有下述做法( ).(2
表象,是指事物不在面前时,人们在头脑中出现的关于事物的形象。具有直观性、概括性、可操作性等特点,在形象思维中具有重要作用。 根据该定义,下列属于表象的是()。
现代运输业的基本运输方式有()。A:铁路运输B:公路运输C:水路运输D:航空运输E:综合运输