Question

    Many people believe the glare(炫目的光) from snow causes snow-blindness. Yet, with dark glasses or not, they may have headaches and watering eyes, and even snow-blindness after several hours of snow light.

The United States army has now found out that glare from snow does not cause snow-blindness in army in a snow-covered country. Rather, a man’s eyes often find nothing to focus on(聚集) in a broad space of snow-covered area. So his long fixed look continually moves and jumps backward and forward over the whole landscape in search of something to look at. Finding something, hour after hour, the eyes never stop searching and the eyeballs become tired and the eye muscles(肌肉) ache. As tears continued increasing, they make eyes difficult to see clearly, and the result is total, even though for a short time, snow-blindness.

Experiments led the Army to a simple method of overcoming(克服) this problem. Scouts(侦察兵) ahead of the army are trained to shake snow from evergreen bushes, creating a line as they cross completely snow-covered landscape. Even the scouts themselves throw lightweight, dark-colored objects ahead on which they can focus too. The men flowing can then see something. Their eyes focus on a bush and having found something to see, stop searching the snow-blanketed landscape. By focusing their attention on one object at a time, the men can cross the snow without becoming hopelessly snow-blind or lost. In this way the problem of crossing a continuous white land is overcome.

1.What is the first paragraph mainly about？

A.The whiteness from snow. B.Snow light and snow blindness.

C.The need for dark glasses. D.Headaches and watering eyes.

2.Snow-blindness can be avoided _____________.

A.by covering the eyeballs with more and more tears

B.by walking ahead and keep looking around

C.by making up for the discomfort of one’s eyes

D.by providing the eyes with something to focus on

3.What is the best title for this passage?

A.Snow-blindness: what it is and whom it influence

B.Snow-blindness: what it is and how nature helps

C.Snow-blindness: how it forms and how to solve it

D.Snow-blindness: how it forms and whom it hurts

4.Which of the following can be inferred from the passage?

A.Solving the problem of snow-blindness is important in army.

B.Snow-blindness was once a big problem but could be cured easily.

C.The glare from snow is considered as the main cause of snow-blindness.

D.Armies around the world pay attention to the problems of snow-blindness.

Answer

1.B

2.D

3.C

4.A

【解析】

本文是一篇说明文。介绍了雪盲的原因和解决办法。

1.段落大意题。根据第一段“Many people believe the glare from snow causes snow-blindness. Yet, with dark glasses or not, they may have headaches and watering eyes, and even snow-blindness after several hours of snow light.”戴不戴眼镜都会产生“雪盲”的症状，如头疼、流泪甚至雪盲，主要讲述了雪盲和雪反射的光的关系。故选B。

2.推理判断题。根据第三段“Even the scouts themselves throw lightweight, dark-colored objects ahead on which they can focus too.”侦察兵的做法告诉我们，雪盲的产生是因为在雪地里眼睛找不到具体目标，由于寻找不到能看的物体才产生雪盲。人们就将灌木上的雪去掉，扔一些深色物体，目的就是有可看的目标，避免雪盲。故选D。

3.主旨大意题。本文介绍了雪盲的原因和解决办法。故选C。

4.细节理解题。据最后一句“In this way the problem of crossing a continuous white land is overcome.”“这样横跨白色大陆的问题才得以克服”可知，解决雪盲的问题对于部队至关重要。故选A。