首页
登录
职称英语
Many people believe the glare from snow causes snow blindness. Yet, dark gla
Many people believe the glare from snow causes snow blindness. Yet, dark gla
游客
2025-05-04
24
管理
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. [br] 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://tihaiku.com/zcyy/4061968.html
相关试题推荐
Beforethemid-nineteenthcentury,peopleintheUnitedStateeatmostfoods
Beforethemid-nineteenthcentury,peopleintheUnitedStateeatmostfoods
Farmersaremoreanxiousforrainthanpeopleincitiesbecausetheyhavemorea
The______actionofthepolicemensavedthepeopleinthehousefrombeingburn
Manypeopleare______toinsectbites,andsomeevenhavetogotohospital.A、i
Thelocalauthoritiesrealizedtheneedtomake______forelderlypeopleinthe
Manypeoplebelievetheglarefromsnowcausessnowblindness.Yet,darkgla
Manypeoplebelievetheglarefromsnowcausessnowblindness.Yet,darkgla
Manypeoplebelievetheglarefromsnowcausessnowblindness.Yet,darkgla
Manypeoplebelievetheglarefromsnowcausessnowblindness.Yet,darkgla
随机试题
TASKONE—ADVANTAGE•Forquestions13—17,matchtheextractswiththeadvantag
•ReadthefollowingextractfromanarticleaboutsmallbusinessinU.S.econom
•Lookatthestatementsbelowandatthefiveextractsontheoppositepagefro
Readthememoandnotebelow.Completetheclaimformgivenbelow.Writewordor
Theannual____ofthedepartmentstorestartstomorrow.A、stockingB、stocktakingC
Eachnumbershownbelowfollowsacertainrule.Figureouttheruleandworkout
P公司是一家专门从事矿产资源开发、生产和销售的大型企业集团公司。2013年末
对正常子宫声像图的描述,不正确的是A.横断面子宫体呈椭圆形 B.子宫体呈均匀的
A.卵巢交界性黏液性囊腺瘤 B.乳腺导管内癌 C.胃中分化腺癌侵及黏膜下层
急性根尖周炎应急处理的主要原则是A:消炎止痛 B:建立引流 C:调牙合止痛
最新回复
(
0
)