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
31
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/Wv2O777K
0
考博英语
相关试题推荐
Therearethreeseparatesourcesofhazard【1】totheuseofnuclearreactiontosupplyuswithenergy.Firstly,theradioactivem
Malariaisaninfectiousparasiticdiseasethatcanbeeitheracuteorchronicandisfrequently______.
Toomuch______canpossiblyleadtounhappiness,eventothoughtsofsuicideasfewpeoplehavethecouragetoanalyzethemselves
NicholasChauvin,aFrenchsoldier,airedhisvenerationofNapoleonBonaparteso______andunceasinglythathebecamethelaugh
Beingcolour-blind,Sallycan’tmakea______betweenredandgreen.
(66)Astateuniversitypresidentwasarrestedtodayandchargedwithimpersonateapoliceofficerbecame,theauthoritiessay,
Tomwasgladthathissuccesswould____forthosewhowouldfollow.
Sinceateacher’sresponseonastudent’spaperispotentiallyaninfluentialtextinawritingclass,weneedtoexamineourpra
Writeanessayonthegiventopic,OnunrestrainedConsumption.Basedonthefollowingoutline,presentyourargumentwithsuppo
随机试题
______attherailwaystationwhenitbegantorain.
化学消毒剂杀菌或抑菌的作用机理是
下列哪条动脉损伤是导致股骨头缺血坏死的主要原因
参苏饮与败毒散的组成中均不含有的药物是
安全评价机构是指依法取得安全评价相应资质,按照资质证书规定的业务范围开展安全评价活动的社会中介服务组织。下列关于安全评价机构获取资质程序的说法,错误的是()
创业风险投资中,政府引导基金的作用包活()。I.支持阶段参股Ⅱ.支持跟进投资Ⅲ.风险补助Ⅳ.投资保障
A股账户按持有人可以分为:自然人证券账户、()、证券公司和基金管理公司等机构证券账户。
根据学生善于模仿、崇拜英雄的特点,教师在教育学生时可以使用()
制度化教育诞生的标志是()
表见代理属于()。
最新回复
(
0
)