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(耀眼的强光)from snow causes snowblindness. Yet, dark glasses or not they find themselves suffering from
Many people believe the glare(耀眼的强光)from snow causes snowblindness. Yet, dark glasses or not they find themselves suffering from
admin
2016-02-04
122
问题
Many people believe the glare(耀眼的强光)from snow causes snowblindness. 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 snowblindness 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(模糊). And the result is total, even though temporary, snowblindness.
Experiments led the Army to a simple method of overcoming this problem. Scouts(侦察兵)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.
Question:
The first paragraph is mainly concerned with______.
选项
A、snow glare and snowblindness
B、the whiteness from snow
C、headaches, watering eyes and snowblindness
D、the need for dark glasses
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/8TPO777K
0
在职攻硕英语联考
相关试题推荐
Itisreportedthat.______adoptedchildrenwanttoknowwhotheirnaturalparentsare.
Sustainabledevelopmentistheonethatmeetstheneedsofthepresentwithout______theabilityoffuturegenerationstomeett
Thereisonefairlystandardreasonwhysomethinkersregardthemeaning-of-lifequestionasbeingitselfmeaningless.Theyargu
Watchingmoviestarslightuponscreenmayincreasetheoddsachildoryoungteenwilltrysmoking,studyfindingssuggest.
BecauseAmericanparentsbelievethatknowledgeleadstoameaningfullife,theytrytogiveyoungstersmanyopportunitiestode
OurculturehascausedmostAmericanstoassumenotonlythatourlanguageisuniversalbutthatthegesturesweuseareunderst
Peoplecanbeaddictedtodifferentthings—e.g.alcohol,drugs,certainfoods,oreventelevision.Peoplewhohavesuchaddit
Intellectualpropertyrightsaretherightsgiventopersonsoverthecreationsoftheirminds.Theyusuallygivethecreatoran
Ifyoudon’thaveyourfilesprotectedwhileworkingonthecomputer,youmighthavethem______byaccident.
James:Philhasdecidedtoquitsmoking.Kim:Again?
随机试题
A.散表寒B.清气分热C.补气养血D.和解少阳E.温中散寒属于针对八纲辨证的功效是()。
以下情况最先换药的应是
下列关于开发区污染源分析的基本原则的有关表述,正确的有()。
某路桥施工公司与B交通局签订了一项公路建造合同,公路总长为50公里,合同规定每公里建造单价600万元,则该合同是()。
A公司2016年发生了1000万元广告费支出,发生时已作为销售费用计入当期损益,并已用银行存款支付。税法规定,该类支出不超过当年销售收入15%的部分允许当期税前扣除,超过部分允许向以后纳税年度结转税前抵扣。A公司2016年实现销售收入5000万元。则A公司
下列各项中,不应计入营业外收入的有()。
如果奇函数f(x)在[3,7]上是增函数且最小值为5,那么f(x)在区间[一7,一3]上是()
几个小朋友开心地表演故事“金色的房子”。这一游戏属于()
广域网和局域网连接是通过()来实现的。
MissBlack,allheirtoalargefortune,isservingalifeterm.
最新回复
(
0
)