Many people believe the glare from snow causes snowblindnenss. 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 glare from snow does not cause snowblindness in troops in a snow-covered country.Rather, a mans eyes frequently find nothing to foucs 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 tsomething to look at. Finding nothing, hour after hour, the eyes never sotp 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 coversthe eyeball in increasing quantity until vision blurs, then is obsured,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 scouring the snow-blanketed lanscape. By focusing their attention on one object at a time,the men can cross the snow without becoming hopelessly snowblind or lost. In this way the problem of crossing a solid white terrain is overcome.
1.To prevent headaches, watering eyes and blindness caused by the glare from snow, dark glasses are_____.
A.indispensible
B.useful
C.ineffective
D.available
2.When the eyes are sore tears are produced to ________.
A.clear the vision
B.remedy snowblindness
C.ease the irritation
D.loosen the muscles
3.Snowblindness may be avoided by_______.
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 foucs on
D.covering the eyeballs with fluid
4.The scouts shake snow from evergreen bushes in order to _______.
A.bive the men behind something to see
B.beautify the landscape
C.warm themselves in the cold
D.prevent the men behind from losing their way
5.A suitable title for this passage would be _______.
A.snowblindness and how to overcome it
B.natrues cure for snowblindness
C.soldiers in the snow
D.snow vision
答案:CCCAA
双语美文:I Wish I Could believe
浪漫英文情书精选:Don't Give Up不要放弃
献给女性:如果生命可以重来
精美散文:27岁的人生
精选英语美文阅读:A Friend's Prayer 朋友的祈祷
如果生命可以重来(双语)
人生哲理:年轻无悔 别停下追寻梦想的脚步
美文:爱的奇迹
精选英语美文阅读:朋友的祈祷
英文《小王子》温情语录
精美散文:爱你所做 做你所爱
浪漫英文情书精选:Is It Love?这是爱么?
精选英语散文欣赏:微笑挽救生命
英语美文欣赏:A beautiful song
英语美文:Keep on Singing
精选英语美文阅读:被忽略的爱 Helpless love
精选英语美文阅读:无雨的梅雨天 (双语)
精选英语散文欣赏:平等的爱
双语美文欣赏:孤独人生
美文阅读:青春物语
美文欣赏:海边漫步
英语美文:A Psalm of Life 人生礼颂
精选英语美文阅读:一封未发出的英文情书《但是你没有》
浪漫英文情书精选:Good Morning早上好
双语散文: Optimism and Pessimistic
爱情英语十句
精选英语美文阅读:哪有一株忘忧草? (双语)
态度决定一切 Attitude Is Everything
浪漫英文情书精选:Need You With Me需要你爱我
浪漫英文情书精选:The Best Surprise最好的惊喜
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |