高考英语阅读理解练习题及答案(7)
出国留学网高考网为大家提供高考英语阅读理解练习题及答案(7),更多高考英语资讯请关注我们网站的更新! 高考英语阅读理解练习题及答案(7) Today I’ll be talking about the invention of the camera and photography. The camera is often thought to be a modern invention, but as early as 1727, a German physicist discovered that light darkens silver salt. Used as a camera, a big box was set up, and a small hole was cut in one side to let the light in; he made temporary pictures on the salt. Silver salt is still the base of the photographic film today. Then a French scientist made the first permanent (永久的) picture by usin... [ 查看全文 ]高考英语阅读理解练习题及答案(7)的相关文章