When we see well, we do not think about our eyes very often. It is only when we cannot see

When we see well, we do not think about our eyes very often. It is only when we cannot see perfectly that we realize how important our eyes are.
People who are near-sighted can only see things that are very close to their eyes. Everything else seems unclear. Many people who do a lot of work, such as writing, reading and sewing become near-sighted.
Then people who are far-sighted endure just the opposite problem. They can see things that are far away, but they have difficulty in reading a book unless they hold it at arm’s length. If they want to do much reading, they must get glasses, too.
Other people do not see clearly because their eyes are not exactly the right shape. They have what is called astigmatism（散光）. This, too, can be corrected by glasses. Some people’s eyes become cloudy because of cataracts（白内障）. Long ago these people often became blind. Now however, it is possible to operate on the cataracts and remove then.
Having two good eyes is important for judging distances. Each eye sees things from a slightly different angle（角度）. To prove this to yourself, look at an object out of one eye; then look at the same object out of your other eye. You will find the object’s relation to the background and other things around it has changed. The difference between these two different eye views helps us to judge how far away an object is. People who have only one eye cannot judge distance as people with two eyes.
【小题1】We should take good care of our eyes . A．only when we can see wellB．only when we cannot see perfectlyC．only when we are near-sighted or far-sightedD．even if we can see well or perfectly【小题2】When things far away seem unclear, one is probably . A．near-sightedB．far-sightedC．astigmaticD．suffering from cataracts【小题3】The underlined word endure in the third paragraph probably means . A．experienceB．imagineC．suffer fromD．recover from【小题4】Having two eyes instead of one is particularly useful for . A．seeing at nightB．seeing objects far awayC．looking over a wide areaD．judging distances【小题5】People who suffer from astigmatism have . A．one eye bigger than the otherB．eyes that are not exactly the right shapeC．a difficulty that can be corrected by an operationD．an eye difficult that cannot be corrected by glasses.D

(答案→)D 解析：文章主要讲述了保护眼睛的重要性。人们往往在视力好的时候忽视对眼睛的保护，正确的做法应该是，无论视力的好与坏，都要注意保护眼睛。【小题1】根据第一段“When we see well, we do not think about our eyes very often. It is only when we cannot see perfectly that we realize how important our eyes are. ”可知，视力正常的时候，人们很少考虑到自己的眼睛，只有看不太清晰的时候，才意识到眼睛的重要性。作者暗含的意思是，呼吁读者平时多注意保护眼睛，即使是在视力正常的时候。故选D。【小题2】根据第二段“People who are near-sighted can only see things that are very close to their eyes.”可知，近视的人，只能看清近处的东西，而不能看清远处的。故选A。【小题3】根据“Then people who are far-sighted endure just the opposite problem.”可知，患有远视的人，有着与近视正好相反的问题。A经历；B想象；C遭受；D从......中恢复，C项常与疾病连用，故选C。【小题4】根据最后一段“Having two good eyes is important for judging distances...The difference between these two different eye views helps us to judge how far away an object is. People who have only one eye cannot judge distance as people with two eyes.”可知，拥有两只眼睛能帮助人们更好地辨别距离，故选D。【小题5】根据第四段“Other people do not see clearly because their eyes are not exactly the right shape. They have what is called astigmatism（散光）.”可知，患有散光的人，他们的眼睛形状不正常，故选B。

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