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(单词翻译:双击或拖选)
There have been many theories to explain the zebra's unmistakable stripes. Scientists have suggested that each zebra has a unique pattern that lets other animals recognise it. Or that the mass of black and white in a vast herd1 provides confusing camouflage2 that puts off predators3.
But this team set out to test exactly what effect the stripes had on a zebra's most irritating and ubiquitous enemy - the blood-sucking horsefly.
As part of their experiment the team put sticky horse models - one white, one black and one zebra-striped - into a fly-infested field. When they collected the flies that had landed and stuck to each of the models, they found that the model zebra attracted by far the fewest flies.
The researchers think that zebras had a black-coated ancestor, which evolved its white stripes in an evolutionary4 arms race, with an insect that's become the biting, disease-carrying scourge5 of most horse herds6.
Quiz
1. True or false? There have been different explanations about why zebras have stripes.
True.
2. The latest scientific reserach shows that stripes give zebras an advantage over their non-striped ancestors. What is it?
The striped pattern makes the zebras much less attractive to insects.
3. What is the main enemy of zebras mentioned in the report?
The horsefly.
4. How different do modern-day zebras look from their ancestors?
They have black and white stripes whereas their ancestors may have looked pure black.
Glossary 词汇表
unmistakable 准确无误的
camouflage 掩体/伪装
predators 食肉动物
irritating 令人烦恼的
ubiquitous 无处不在的
horsefly 马蝇
fly-infested 充满苍蝇的
ancestor 祖先
evolved 进化
scourge 天灾/瘟疫
1 herd | |
n.兽群,牧群;vt.使集中,把…赶在一起 | |
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2 camouflage | |
n./v.掩饰,伪装 | |
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3 predators | |
n.食肉动物( predator的名词复数 );奴役他人者(尤指在财务或性关系方面) | |
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4 evolutionary | |
adj.进化的;演化的,演变的;[生]进化论的 | |
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5 scourge | |
n.灾难,祸害;v.蹂躏 | |
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6 herds | |
兽群( herd的名词复数 ); 牧群; 人群; 群众 | |
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