To become transparent, an animal needs to keep its body from absorbing or scattering light. Living materials can stop light because they contain pigments(色素) that absorb specific colors of light. But a transparent animal doesn’t have pigments, so its tissues won’t absorb light. According to Johnsen, avoiding absorption is actually easy. The real challenge is preventing light from scattering.
Animals are built of many different materials----skin, fat, and more----and light moves through each at a different speed. Every time light moves into a material with a new speed, it bends and scatters. Transparent animals use different tricks to fight scattering. Some animals are simply very small or extremely flat. Without much tissue to scatter light, it is easier to be see—through. Others build a large, clear mass of non-living jelly-lie(果冻状的)material and spread themselves over it .
Larger transparent animals have the biggest challenge, because they have to make all the different tissues in their bodies slow down light exactly as much as water does. They need to look uniform. But how they’re doing it is still unknown. One thing is clear for these larger animals, staying transparent is an active process. When they die, they turn a non-transparent milky white.
63. According to Paragraph 1, transparent animals_______.
A. stay in groups
B. can be easily damaged
【近三年高考(2017-2016)英语试题分项版解析:专题16 科普类说明文(原卷版)】相关文章:
★ 河南省三门峡市2014高考英语一轮(暑假)基础训练(10)附答案
★ 2017高考四川省广安市英语阅读理解一轮系列训练:26(含解析)
★ 2017年高考英语二轮复习精品资料:专题15 完形填空(教学案)(原卷版)
★ 河南省三门峡市2014高考英语一轮(暑假)基础训练(5)附答案
★ 2017高考四川省广安市英语阅读理解一轮系列训练:24(含解析)
★ 天津市武清区杨村第四中学2016届高考英语一轮复习语法专题六《定语从句》课件外研版
最新
2017-04-24
2017-04-24
2017-04-24
2017-04-24
2017-04-21
2017-04-21