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2011-09-27 16:13:00   来源：作文地带    双击单词自动翻译

　　(C)Magnifying glass was not used as a visual aid until the thirteenth century, when Roger Bacon inverted eyeglasses.

　　(D) Artisans today are unable to reproduce the miniature engravings of ancient 美国GREek artisans without the aid of high-powered magnifying lenses, first produced in the thirteenth century.

　　(E) The eyesight of nearsighted individuals and those with ordinary vision is not significantly different if the objects viewed are less than a few feet away.