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
2013-01-20
25
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.
The first paragraph is mainly concerned with________.
选项
A、snow glare and snow blindness
B、the whiteness from snow
C、headaches, watering eyes and snowb lindness
D、the need for dark glasses
答案
A
解析
雪的强光(snow glare)以及雪盲(snowblindness)是这篇谈论的重点,因此选择A答案。
转载请注明原文地址:https://kaotiyun.com/show/Xv2O777K
0
考博英语
相关试题推荐
Blackpeoplearebynomeans______whitepeople.
Heseemedreluctanttosendhistroopsinanefforttodiscouragethe______peasants.
(66)Astateuniversitypresidentwasarrestedtodayandchargedwithimpersonateapoliceofficerbecame,theauthoritiessay,
Therearethreegeneralmethodspeopleusetoexplainandunderstandtheirworld:beliefs,pseudo-science,andscience.Whata
Aslongasherparentscanremember,13-year-oldKatieHarthasbeentalkingaboutgoingtocollege.Hermother,Tally,afinanc
Biologically,thereisonlyonequalitywhichdistinguishesusfromanimals:theabilitytolaugh.Inauniversewhichappearst
ThesenatorofNewYorkcourtedblackvoters,consideredcrucialto______theDemocraticpresidentialnomination,inaseriesof
UnlessIwas____mistaken,therewassomethingwrongwithLouise.
Inthispart,youarerequiredtowriteacompositionentitledAchievementsChinaHasMadeandSomeofItsProblemstoBeSolved
随机试题
鲁迅的第一篇白话小说是( )
A.固本益肠丸B.四神丸C.参苓白术散D.加味保和丸E.香连丸治疗湿热内蕴之泄泻,宜选用的中成药是()。
外籍个人威廉姆斯先生(在中国境内无住所)受美国其任职的某机构委托来华工作,2019年6月10日来华,8月2日回美国处理公务,8月10日返回中国,8月31日完成在华工作,回到美国。在华工作期间,中国企业每月向威廉姆斯先生支付工资60000元,同时其所在外国机
在人群心理学中,人们把替罪羊引起的心理效应现象,称之为替罪羊效应。替罪羊原指古代犹太教在赎罪口用做祭品的羊,表示由它替人受罪,后比喻代人受过的人。根据上述定义,下列属于替罪羊效应的是()。
ERG理论是阿尔德福尔于1969年提出的一种与马斯洛需求层次理论密切相关但又有些不同的理论。他把人的需要分为三类,包括()
为什么说教育对人的发展起主导作用?
课外、校外教育的主要特点是()
提前解除收容教育的,实际执行的收容教育期限不得少于原决定期限的三分之二。()
一本书有100多页,小王每天看固定的页数,看了18天后,发现未看的页数正好是已看页数的,又看了7天后发现未看的页数正好比已看的页数少100页。问这本书共有多少页?()
Interrelationshipfragmentedmacrocosmbewilderedmicrocosmfacilitatedependencyrecognizedi
最新回复
(
0
)