Question

    It is a question that has long puzzled scientists—exactly why are tigers orange? One might think it makes them more obvious-particularly against a leafy green forest background. William Blake summed it up in his famous poem known by generations of schoolchildren: “Tyger, tyger, burning bright / In the forest of the night.” But now the answer is at hand.

While obvious to us, computer simulations (模拟) of what the big cats look to the main animals they hunt for, deer, show a different picture. Humans with normal colour vision, can see red, blue and green colours. But deer can only pick up blue and green light, they are effectively colourblind to the colour red, like some humans. It means the tigers’ orange colouration looks green to them, allowing them to mix perfectly into the background, new research claims.

Dr John Fennell at the University of Bristol and colleagues said that they used computers to estimate how noticeable a given animal was. They did this by using images of the environment in which the animal lives, and then creating images to see whether the camouflage helps the animal to mix in.

Dr Fennell writes that by simulating what the world looks like to animals who are “two-colour vision”—someone who cannot discover the difference between red and green—“we also identify the most suitable colours for hiding and visibility”.

Dr Fennell writes in the Royal Society Journal Inter face: “Considering the coat of a tiger, it has fur that appears orange to a three-colour vision observer rather than some shade of green, though the latter should be more appropriate color for an attack hunter in forests. However, when viewed as a two-colour vision observer, the tiger’s colour is very effective.”

The question then arises as to why tigers don’t grow green coats. Dr Fennell and colleagues write that mammals (哺乳动物) are not able to produce green fur. To do so would “require a significant change to mammalian biochemistry”. There is only one mammal known to have green fur but this is achieved through what might be considered as, well, cheating, not exactly real.

1.Why does the author mention the poem in paragraph 1?

A.To arouse reader s interest in poems.

B.To show the authors respect to the poet.

C.To answer the question of the color of the tiger

D.To stress the noticeable color of the tiger to us.

2.What color is inexistent in the eyes of deer?

A.Black. B.Red.

C.Blue. D.Green.

3.What does the underlined word “camouflage” mean in paragraph 3?

A.The cover of something.

B.The images of something.

C.The way of hiding something.

D.The way of hunting for something.

4.What can be inferred from the last paragraph?

A.The colour of tigers sometimes cheats people.

B.Getting green may prevent tigers from being extinct.

C.There are no mammals with real green fur in the world.

D.The tigers’ fur will probably evolve into green in the future.

Answer

1.D

2.B

3.C

4.C

【解析】

这是一篇说明文。为什么老虎是橙色的？这个长期困扰科学家的问题终于被科学家们破解了。

1.推理判断题。根据第一段中的It is a question that has long puzzled scientists—exactly why are tigers orange? One might think it makes them more obvious-particularly against a leafy green forest background.可知，这是一个长期困扰科学家的问题——为什么老虎是橙色的?有人可能会认为这让它们变得更加显眼——尤其是在茂密的绿色森林背景下。所以通过提到英国诗人和画家威廉·布雷克的一首诗的内容可以判断出，此处是为了例证文章开头的陈述——对于我们人类来说，老虎的颜色太显眼了。故选D。

2.细节理解题。根据第二段中的It means the tigers’ orange colouration looks green to them, allowing them to mix perfectly into the background, new research claims.以及第四段 中的...animals who are “two-colour vision”— someone who cannot discover the difference between red and green.可知，这意味着老虎的橙色在它们看来是绿色的，这使得老虎可以完美地融入周围的背景，双基色的动物无法分辨红色和绿色，也就是说，在鹿的眼中是没有红色系的颜色。故选B。

3.词义猜测题。根据第三段中的They did this by using images of the environment in which the animal lives, and then creating images to see whether the camouflage helps the animal to mix in.可知，他们通过使用动物所处环境的图像来做到这一点，然后创建图像来观察伪装方式是否有助于动物分不清它们。所以通过上下文的语境可以判断出，第3段下划线的camouflage一词是指隐藏的方式。故选C。

4.推理判断题。根据最后一段中的mammals (哺乳动物) are not able to produce green fur. There is only one mammal known to have green fur but this is achieved through what might be considered as, well, cheating, not exactly real.可知，哺乳动物无法长出绿色皮毛。世上已知的哺乳动物中只有一种有绿色皮毛但却是通过被认为可能是欺诈的手段才实现的，不是真正的绿色。所以通过关键词are not able to produce green fur, cheating, not exactly real可推断出，世界上没有绿色皮毛的哺乳动物。故选C。