E
Many people believe the glare from snow causes snow blindnenss. Yet, dark glasses or not, they find themselves suffering from headaches and watering eyes, and even snowblindness, when ex- posed to several hours of "snow light".
The United States army has now determined that 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 barren snow-covered terrain. 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 muscles ache. Nature offsets this irritation by producing more and fluid which covers the eyeball. The fluid covers the eyeball in increasing quantity until vision blurs, then is observed, and the result is total, even though temporary, snow blindness.
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.
Snow blindness 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 focus on D:covering the eyeballs with fluid
Nearly ______ of the earth ______ covered by se
A:a．there fourth；is B:three fourths；is C:three fourth；are D:three fourths；are
Bathing In the Sea
Bathing in the sea in England a hundred years ago was not quite the light-hearted amusement that it is today. There are no running down from the hotel to the beach in a bath robe(长袍) , no sunbathing, or lying about on the sands in bathing-dresses after the dip. Everything had to be done in an orderly and extremely polite manner. Mixed bathing was not allowed anywhere. Men and women each had their separate part of the beach, and they were not supposed to meet in the water.
Bathing clothes were also closely controlled. Men usually wore simple bathing drawers and no more, but women were obliged to wear thick, cumbersome woolen garments that covered them completely from head to foot. These satisfied the demands of modesty, but they must have been extremely uncomfortable for swimming.
Even thus decently covered, women were not supposed to show themselves on the beach while in bathing attire(浴衣). They had to wait their turn for a bathing machine, a sort of wooden cabin on wheels which was drawn right down to the waters edge by horses. On its seaward side a sort of hood or canopy(罩盖) stretched outwards and downwards over the water, completely hiding the bather until she was actually in the sea, There was a bathing woman in attendance, part of whose duty was to dip, in other words, to seize the bather as soon as she emerged and dip her forcibly under water two or three times. This was supposed to be for the benefit of her health, and no doubt it was all right in the hands of the gentle. But most bathing women were the reverse of gentle, and to be dipped by them must have been a strenuous form of exercise.
Women wore uncomfortable bathing clothes because______.
A:it protected them from the cold B:it was considered bad manners to show any flesh C:it made it easier to swim D:it covered them from head to foot
E
Many people believe the glare from snow causes snow blindnenss. Yet, dark glasses or not, they find themselves suffering from headaches and watering eyes, and even snowblindness, when ex- posed to several hours of "snow light".
The United States army has now determined that 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 barren snow-covered terrain. 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 muscles ache. Nature offsets this irritation by producing more and fluid which covers the eyeball. The fluid covers the eyeball in increasing quantity until vision blurs, then is observed, and the result is total, even though temporary, snow blindness.
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.
Snow blindness 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 focus on D:covering the eyeballs with fluid
E
Many people believe the glare from snow causes snow blindnenss. Yet, dark glasses or not, they find themselves suffering from headaches and watering eyes, and even snowblindness, when ex- posed to several hours of "snow light".
The United States army has now determined that 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 barren snow-covered terrain. 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 muscles ache. Nature offsets this irritation by producing more and fluid which covers the eyeball. The fluid covers the eyeball in increasing quantity until vision blurs, then is observed, and the result is total, even though temporary, snow blindness.
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.
Snow blindness 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 focus on D:covering the eyeballs with fluid
E
Many people believe the glare from snow causes snow blindnenss. Yet, dark glasses or not, they find themselves suffering from headaches and watering eyes, and even snowblindness, when ex- posed to several hours of "snow light".
The United States army has now determined that 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 barren snow-covered terrain. 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 muscles ache. Nature offsets this irritation by producing more and fluid which covers the eyeball. The fluid covers the eyeball in increasing quantity until vision blurs, then is observed, and the result is total, even though temporary, snow blindness.
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.
Snow blindness 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 focus on D:covering the eyeballs with fluid
单选题
