Defense of Animal托福听力原文翻译及问题答案

新托福听力难度大，题型多，而且听力和写作、口语等部分也相关联，可以说，是牵一发而动全身的地位。所以要想取得高分，需要以残酷的、毫无疑问的、不存在任何侥幸的听力实力为基础。那么关于“Defense of Animal托福听力原文翻译及问题答案”的内容，下面由小编来给大家分享。

Defense of Animal托福听力原文翻译及问题答案

一、Defense of Animal托福听力原文：

One of the most important relationships between different animal species is predation—the predator-prey interaction,in which a predator eats a prey.Predator species have several adaptations that help them catch prey species.Prey species have adaptations,too—physical and behavioral adaptations that enable them to elude predators and avoid being eaten.These defensive adaptations evolved in prey species through repeated encounters with predators over evolutionary time.

Some animal defenses are passive,such as hiding.Some defenses are active,such as escaping.Fleeing—running away—is the most direct anti-predator response,but it requires the animal to expend a lot of energy.A rabbit uses up a lot of energy running away from a lynx.Many animals avoid expending too much energy by escaping into a shelter.

Several prey species have some sort of vocalization—an alarm call—to announce the presence of a predator.The alarm call often triggers a behavioral defense called mobbing.During mobbing,the prey turns the tables and attacks the predator.

For example,when a chickadee spots a threat—say,an owl—it calls out the alarm.The chickadee starts scolding the owl,sometimes actually striking it from behind.Birds of other species may fly in to investigate,and often participate in the mobbing.The other birds chase,dive-bomb,or surround the owl,usually vocalizing loudly.Their intent is to encourage the“enemy”to move on to another area.

Some animals rely on defensive coloration.A well-known example of defensive coloration is camouflage,which makes prey difficult to spot against a background of similar color.All a camouflaged animal has to do is remain still to avoid being seen.Thus,camouflage is probably the most effective passive defense.Incidentally,some predators also use camouflage,especially predators who lie in wait for prey and have to blend into their environment.

Moths that camouflage themselves to match a leaf stand a good chance of not being seen by moth-eating birds,unless,of course,the moths become so populous that a bird is likely to come across one by accident.Once the bird learns the moth’s identity,it has a search image for it,and the moth’s disguise is useless.Looking like a leaf is then no advantage because the bird will start pecking at leaves in the hope that they are moths,and it will keep doing it as long as a sufficient number do turn out to be moths.

Another animal defense is the use of chemical weapons.We’re all familiar with the chemical weapon of the skunk.

Some animals—like poisonous toads and frogs—can synthesize toxins that attack the nervous system of predators.Other animals acquire chemical defenses passively.For example,some caterpillars acquire poison from the plants they eat.Then,when a bird eats the caterpillar,the bird quickly vomits.After that,the bird will avoid eating that kind of caterpillar.Some birds can remember bad-tasting meals a year later.

Another defensive adaptation is warning coloration.Animals with effective chemical defenses are often brightly colored,and there is evidence that predators are more cautious in dealing with bright color patterns in potential prey.This is probably because a lot of poisonous or bad-tasting animals are colored brightly,with black and yellow,or black and red stripes.

Warning coloration quickly trains predators to avoid eating these brightly-colored animals.Some birds have an instinctive tendency to avoid eating insects with warning coloration.For example,young warblers leave wasps alone because the birds recognize the danger in the black and yellow stripes of the wasp.However,warning coloration is not an absolute defense,as there is also evidence showing that many birds occasionally feed on bees and wasps,perhaps after learning to cope with their chemical defenses.

二、Defense of Animal托福听力中文翻译：

不同动物物种之间最重要的关系之一是捕食——捕食者与猎物的相互作用，即捕食者吃掉猎物。捕食者有几种适应能力，可以帮助它们捕捉猎物。猎物有适应能力，也有身体和行为适应能力，使它们能够躲避捕食者，避免被吃掉。随着进化时间的推移，这些防御适应在猎物物种中通过反复遭遇捕食者而进化。

有些动物的防御是被动的，比如躲藏。有些防御是主动的，比如逃跑。逃跑是最直接的反捕食者反应，但这需要动物消耗大量能量。兔子在逃离山猫时消耗了大量的能量。许多动物为了避免消耗过多的能量而逃到收容所。

一些猎物会发出某种叫声——发出警报，宣布捕食者的存在。警报呼叫通常会触发一种称为暴徒的行为防御。在围捕过程中，猎物会翻盘攻击捕食者。

例如，当山雀发现威胁时，比如猫头鹰，它会发出警报。山雀开始斥责猫头鹰，有时甚至会从后面打它。其他物种的鸟类可能会飞过来调查，并经常参与围捕。其他鸟类追逐、俯冲轰炸或包围猫头鹰，通常大声鸣叫。他们的意图是鼓励“敌人”转移到另一个地区。

有些动物依靠防御色。防御色的一个著名例子是伪装，它使猎物在类似颜色的背景下很难被发现。一只伪装的动物所要做的就是保持静止以避免被人看到。因此，伪装可能是最有效的被动防御。顺便说一句，一些捕食者也会使用伪装，尤其是那些埋伏着等待猎物并不得不融入环境的捕食者。

为了与树叶相匹配而伪装自己的飞蛾很有可能不会被吃飞蛾的鸟类看到，当然，除非飞蛾数量如此之多，以至于鸟类很可能会偶然遇到一只。一旦鸟知道了飞蛾的身份，它就会有一个搜索图像，而飞蛾的伪装是无用的。看起来像一片叶子是没有好处的，因为这只鸟会开始啄树叶，希望它们是飞蛾，只要有足够数量的飞蛾出现，它就会一直这样做。

另一种动物防御是使用化学武器。我们都熟悉臭鼬的化学武器。

一些动物，如有毒的蟾蜍和青蛙，可以合成毒素攻击捕食者的神经系统。其他动物被动地获得化学防御。例如，一些毛虫从它们吃的植物中获取毒素。然后，当一只鸟吃了毛毛虫时，它会很快呕吐。在那之后，这只鸟将避免吃那种毛毛虫。有些鸟一年后还记得难吃的饭菜。

另一种防御适应是警告色。具有有效化学防御能力的动物通常颜色鲜艳，有证据表明，捕食者在处理潜在猎物的鲜艳颜色时更加谨慎。这可能是因为许多有毒或味道不好的动物颜色鲜艳，有黑色和黄色，或黑色和红色条纹。

警告色能迅速训练捕食者避免食用这些颜色鲜艳的动物。一些鸟类本能地倾向于避免食用带有警告色的昆虫。例如，年轻的莺不理黄蜂，因为这些鸟从黄蜂的黑色和黄色条纹中认识到了危险。然而，警告色并不是绝对的防御，因为也有证据表明，许多鸟类偶尔会以蜜蜂和黄蜂为食，也许是在学会应对它们的化学防御之后。

三、Defense of Animal托福听力问题：

Q1:1.What topics does the professor mainly discuss?

Click on two answers.

A.How predators find,catch,and eat prey

B.Behaviors that help prey avoid predators

C.Changes in predator and prey populations

D.Defensive coloration in prey animals

Q2:2.Why does the professor say this:

A.To explain why prey animals must be fast runners

B.To compare the amount of energy used by predators and prey

C.To illustrate a disadvantage of an active anti-predator response

D.To give an example of an adaptation that benefits predators

Q3:3.What takes place during a mobbing event?

A.A prey animal runs away from a predator.

B.Prey species chase,scold,and attack a predator.

C.Predators join together in a group to hunt prey.

D.The population of a prey species increases rapidly.

Q4:4.Why does the professor say this:

A.To explain why camouflage is not a perfect defense

B.To imply that birds and moths evolved at the same time

C.To describe how birds use their eyesight to find food

D.To compare the survival strategies of birds and moths

Q5:5.What does the professor mean when she says this:

A.Some birds have discovered that brightly-colored insects taste good.

B.Some birds have chemical defenses similar to those of insects.

C.Some birds appear able to manage the poison of bees and wasps.

D.Some birds may have forgotten the meaning of bright coloration.

四、Defense of Animal托福听力答案：

A1:正确答案：BD

A2:正确答案：C

A3:正确答案：B

A4:正确答案：A

A5:正确答案：C