2012考研英语辅导作文素材视觉(Vision)
Human vision like that of other primates has evolved in an arboreal environment. In the dense complex world of a tropical forest, it is more important to see well that to develop an acute sense of smell. In the course of evolution members of the primate line have acquired large eyes while the snout has shrunk to give the eye an unimpeded view.
Of mammals only humans and some primates enjoy color vision. The red flag is black to the bull. Horses live in a monochrome world .light visible to human eyes however occupies only a very narrow band in the whole electromagnetic spectrum.
Ultraviolet rays are invisible to humans though ants and honeybees are sensitive to them. Humans though ants and honeybees are sensitive to them. Humans have no direct perception of infrared rays unlike the rattlesnake which has receptors tuned into wavelengths longer than 0.7 micron.
The world would look eerily different if human eyes were sensitive to infrared radiation. Then instead of the darkness of night, we would be able to move easily in a strange shadowless world where objects glowed with varying degrees of intensity. But human eyes excel in other ways.
They are in fact remarkably discerning in color gradation. The color sensitivity of normal human vision is rarely surpassed even by sophisticated technical devices.
猜你喜欢
-
- 03-08考研英语真题“细读”三标准详解
- 03-08考研英语:真题的正确打开方式
- 03-08考研英语翻译:评分标准及最好的复习材料
- 03-08看美剧能提高考研英语翻译?做题去吧
- 03-082018考研英语背单词的最本质是反复记忆
- 03-08掌握这些后缀,考研英语单词更简单了!
- 03-082018年考研了解西方文化更有助于考研英语阅读提高
- 03-08怎么背单词更快?考研英语词根变化规律总结
- 03-08考研英语句子插入结构翻译?
- 03-08学会这批考研英语长难句,翻译提升一个档次