阅读理解: The United States army has now decided that strong light from snow does no

阅读理解：

    The United States army has now decided that strong light from snow does not cause snowblindness in troops in a snow-covered country. Rather, a man’s eyes always find nothing to fix on in a wide open snow-covered area. So his gaze(凝视) continually changes and jumps back and forth over the entire area in search of something to look at. Finding nothing, hour after hour, the eyes never stop searching and eyeballs become painful and eye muscles ache. Then tears keep coming out and covering the eyeball in increasing quantity until vision becomes unclear, and the result is total snowblindness.

    Experiments have led the army to a simple method of overcoming this problem. Scouts(侦察员) ahead of a main body of troops are trained to shake snow from evergreen bushes, making a dotted line as they cross a completely snow-covered area. Even the scouts themselves throw light weight, dark colored things ahead on which they too can fix their eyes. The men following can then see something. In this way they can cross the snow without becoming hopelessly snowblind or lost. Thus the problem of crossing a solid white area is overcome.

1．The eyeballs become painful and eye muscles ache because ______.

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A．tears cover the eyeballs

B．of the blinding sunlight

C．of the blinding snow

D．there’s nothing to fix on

2．Snowblindness may be avoided by ______.

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A．fixing on the solid white area

B．providing the eyes with something to fix on

C．searching for something to look at in the snow-covered country

D．covering the eyeballs with tears

3．The scouts shake snow from evergreen bushes in order to ______.

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A．give the men behind something to see

B．make that area more beautiful

C．warm themselves in the cold

D．prevent the men behind from losing their way

4．According to the writer, recent work on snowblindness shows that it is caused by ______.

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A．exposure(暴露) to bright light

B．failure to fix on an object

C．a loss of vision for a short while

D．always fixing on dark colored objects

5．Which of the following titles is most fit for this passage? ______.

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A．Snowblindness and How to Overcome It

B．How to Do Experiments to Prevent Snowblindness

C．Soldiers in the Snow

D．Snow Is No Good for the Army

试题答案

答案：D;C;A;A;A