患者男性，59岁，因“突发眩晕伴恶心、呕吐3小时”就诊，晨起后突然感到眩晕和身体不稳，伴恶心、呕吐，平躺休息后1分钟左右可自行缓解，翻身时再次引起眩晕发作，无耳鸣耳聋。查体：意识清，精神差，头位变化时可诱发头晕，伴水平眼震，无听力障碍，余脑神经检查未见明显阳性体征，四肢肌力5级，双侧指鼻试验阴性，跟膝胫试验阴性，病理反射未引出。颅脑MRI未见异常。
其最主要的病因是（）
When we see well, we do not think about our eyes very often. (76) 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 blurry (unclear). Many people who do a lot of work, such as writing, reading and sewing, become near-sighted.
People who are far-sighted suffer from 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, lf 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 them.
A. seeing at night
B. seeing objects far away
C. looking over a wide area
D. judging distances
In ancient times the most important examinations were spoken, not written. In the schools of ancient Greece and Rome, testing usually consisted of saying poetry aloud or giving; speeches.
In the European universities of the middle Ages, students who were working for advanced degrees had to discuss questions in their field of study with people who had made a special study of the subject. This custom exists today as part of the process of testing candidates(考生) for the doctor’ s degree.
Generally, however, modern examinations are written. The written examination, where all students are tested on the same questions, was probably not known until the nineteenth century. Perhaps it came into existence with the great increase in population and the development of modern industry. A room full of candidates for a state examination, timed exactly by electric clocks and carefully watched over by managers, resembles a group of workers at an automobile factory. Certainly,
A. personal
B. spoken
C. objective
D. written
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