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Official11托福阅读Passage3Begging by Nestlings文本+题目原文+答案解析【雷哥托福】

2019-01-25 10:02:16 发布 来源:雷哥托福

TPO11托福阅读Passage3Begging by Nestlings文本+题目原文+答案解析

Begging by Nestlings

Many signals that animals make seem to impose on the signalers costs that are overly damaging. [■] A classic example is noisy begging by nestling songbirds when a parent returns to the nest with food.[■] These loud cheeps and peeps might give the location of the nest away to a listening hawk or raccoon, resulting in the death of the defenseless nestlings. [■] In fact, when tapes of begging tree swallows were played at an artificial swallow nest containing an egg, the egg in that “noisy” nest was taken or destroyed by predators before the egg in a nearby quiet nest in 29 of 37 trials.[■]

Further evidence for the costs of begging comes from a study of differences in the begging calls of warbler species that nest on the ground versus those that nest in the relative safety of trees. The young of ground-nesting warblers produce begging cheeps of higher frequencies than do their tree-nesting relatives. These higher-frequency sounds do not travel as far, and so may better conceal the individuals producing them, who are especially vulnerable to predators in their ground nests. David Haskell created artificial nests with clay eggs and placed them on the ground beside a tape recorder that played the begging calls of either tree-nesting or of ground-nesting warblers. The eggs “advertised” by the tree-nesters' begging calls were found bitten significantly more often than the eggs associated with the ground-nesters' calls.

The hypothesis that begging calls have evolved properties that reduce their potential for attracting predators yields a prediction: baby birds of species that experience high rates of nest predation should produce softer begging signals of higher frequency than nestlings of other species less often victimized by nest predators. This prediction was supported by data collected in one survey of 24 species from an Arizona forest, more evidence that predator pressure favors the evolution of begging calls that are hard to detect and pinpoint.

Given that predators can make it costly to beg for food, what benefit do begging nestlings derive from their communications? One possibility is that a noisy baby bird provides accurate signals of its real hunger and good health, making it worthwhile for the listening parent to give it food in a nest where several other offspring are usually available to be fed. If this hypothesis is true, then it follows that nestlings should adjust the intensity of their signals in relation to the signals produced by their nestmates, who are competing for parental attention. When experimentally deprived baby robins are placed in a nest with normally fed siblings, the hungry nestlings beg more loudly than usual—but so do their better-fed siblings, though not as loudly as the hungrier birds.

If parent birds use begging intensity to direct food to healthy offspring capable of vigorous begging, then parents should make food delivery decisions on the basis of their offsprings calls. Indeed, if you take baby tree swallows out of a nest for an hour feeding half the set and starving the other half, when the birds are replaced in the nest, the starved youngsters beg more loudly than the fed birds, and the parent birds feed the active beggars more than those who beg less vigorously.

As these experiments show, begging apparently provides a signal of need that parents use to make judgments about which offspring can benefit most from a feeding. But the question arises, why don't nestlings beg loudly when they aren't all that hungry? By doing so, they could possibly secure more food, which should result in more rapid growth or larger size, either of which is advantageous. The answer lies apparently not in the increased energy costs of exaggerated begging—such energy costs are small relative to the potential gain in calories— but rather in the damage that any successful cheater would do to its siblings, which share genes with one another. An individual's success in propagating his or her genes can be affected by more than just his or her own personal reproductive success. Because close relatives have many of the same genes, animals that harm their close relatives may in effect be destroying some of their own genes. Therefore, a begging nestling that secures food at the expense of its siblings might actually leave behind fewer copies of its genes overall than it might otherwise.

TPO11托福阅读Passage1Begging by Nestlings题目

Question 1 of 14: paragraph 1:the phrase“impose on”  in the passage is closest in meaning to

A.increase for

B. remove from

C. place on

D.distribute to

Question 2 of 14: According to paragraph 1, the experiment with tapes of begging tree swallows establishes which of the following?

A.Begging by nestling birds can attract the attention of predators to the nest.

B. Nest predators attack nests that contain nestlings more frequently than they attack nests that contain only eggs

C. Tapes of begging nestlings attract predators to the nest less frequently than real begging calls do.

D. Nest predators have no other means of locating bird nests except the begging calls of nestling birds.

Question 3 of 14: Paragraph 2: The word “artificial” in the passage is closest in meaning to

A. attractive

B. not real

C. short-term

D. well designed

Question 4 of 14: Paragraph 2 indicates that the begging calls of tree nesting warblers

A.put them at more risk than ground-nesting warblers experience

B.can be heard from a greater distance than those of ground-nesting warblers

C.are more likely to conceal the signaler than those of ground-nesting warblers

D.have higher frequencies than those of ground nesting warblers

Question 5 of 14: The experiment described in paragraph 2 supports which of the following conclusions?

A. Predators are unable to distinguish between the begging cheeps of ground-nesting and those of tree-nesting warblers except by the differing frequencies of the calls.

B. When they can find them, predators prefer the eggs of tree-nesting warblers to those of ground-nesting warblers.

C. The higher frequencies of the begging cheeps of ground-nesting warblers are an adaptation to the threat that ground-nesting birds face from predators

D. The danger of begging depends more on the frequency of the begging cheep than on how loud it is.

Question 6 of 14: Paragraph 3:The word“ prediction” in the passage is closest in meaning to

A. surprise

B. discovery

C. explanation

D. expectation

Question 7 of 14: The word“pinpoint”in the passage is closest in meaning to

A. observe

B. locate exactly

C. copy accurately

D. recognize

Question 8 of 14:  Paragraph 4: The word“ derive ”in the passage is closest in meaning to

A. require

B. gain

C. use

D. produce

Question 9 of 14: In paragraphs 4 and 5, what evidence supports the claim that the intensity of nestling begging calls is a good indicator of which offspring in a nest would most benefit from a feeding?

A.When placed in a nest with hungry robins, wellfed robins did not beg for food.

B. Among robin nestlings, the intensity of begging decreased the more the nestlings were fed.

C.Hungry tree swallow nestlings begged louder than well-fed nestlings in the same nest.

D. Hungry tree swallow nestlings continued to beg loudly until they were fed whereas well-fed nestlings soon stopped begging.、

Question 10 of 14: It can be inferred from paragraphs 4 and 5 that parent songbirds normally do not feed

A.nestlings that are too weak to beg for food as vigorously as their nestmates

B. more than one hungry nestling during a single visit to the nest

C.offspring that were fed by the parents on the previous visit to the nest

D.nestlings that have been removed and then later put back into their nest

Question 11 of 14:In paragraph 6, the author compares the energy costs of vigorous begging with the potential gain in calories from such begging in order to

A.explain why begging for food vigorously can lead to faster growth and increased size.

B.explain how begging vigorously can increase an individual’s chance of propagating its own genes

C.point out a weakness in a possible explanation for why nestlings do not always beg vigorously

D.argue that the benefits of vigorous begging outweigh any possible disadvantages

Question 12 of 14:According to paragraph 6, which of the following explains the fact that a well-fed nestling does not beg loudly for more food?

A.There is no benefit for a nestling to get more food than it needs to survive.

B. By begging loudly for food it does not need, a nestling would unnecessarily expose itself to danger from predators.

C. If a nestling begs loudly when it is not truly hungry, then when it is truly hungry its own begging may be drowned out by that of its well-fed siblings.

D. More of a nestling's genes will be passed to the next generation if its hungry siblings get enough food to survive.

Question 13 of 14: Look at the four squares [■] that indicate where the following sentence could be added to the passage. Where would the sentence best fit?

The cheeping provides important information to the parent, but it could also attract the attention of others.

Question 14 of 14:Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that not presented in the passage or are minor ideas in the passage. This question is worth 2 points. Experiments have shed much light on the begging behaviors of baby songbirds

A. Songbird species that are especially vulnerable to predators have evolved ways of reducing the dangers associated with begging calls.

B. Songbird parents focus their feeding effort on the nestlings that beg loudest for food.

C. It is genetically disadvantageous for nestlings to behave as if they are really hungry when they are not really hungry.

D. The begging calls of songbird nestlings provide a good example of overly damaging cost to signalers of signaling.

E. The success with which songbird nestlings communicate their hunger to their parents is dependent on the frequencies of the nestlings' begging calls.

F. Songbird nestlings have evolved several different ways to communicate the intensity of their hunger to their parents.

TPO11托福阅读Passage3Begging by Nestlings真题解析

Question 1 of 14


解析:impose on“施加影响,强迫”,所以答案place on“施加”是正确答案。


Question 2 of 14


解析:以tapes of begging tree swallows 作为定位关键词,看最后两句,说到的是nestling songbirds 发出的巨大的cheeps 和 peeps 声可能会对听到的hawk和raccoon暴露位置,导致了这些无抵抗能力的nestling birds的死亡。然后in fact 列举了一个例子,录有begging tree swallows的磁带放在了有鸟蛋的人造巢里的时候做测试的时候,被附近的predators 拿走或者毁坏的几率29/37。结合选项,整个实验是为了说明A。段落里没有涉及有幼雏和eggs的比较,没有人工tapes声音和真实的鸟的乞食声的比较,也没有说明Nest predators是否只有一种或者多种方法定位鸟巢。所以剩下三个选项都不对。

Question 3 of 14


解析:artificial“人造的,人工的”,所以答案not real不真实的正确。原文说这个人做了一个什么样的nest,之前的句子说幼鸟在ground nest很容易受攻击,紧接着就说做了一个nest,肯定是假的,A“吸引人的”,C“短期的”D“设计得很好的”都不恰当。

Question 4 of 14


解析:关键词是tree nesting warblers,第一句说,乞食声所带来的代价的进一步证据来自一个研究,这个研究是关于巢在地面上的warbler speices 和那些巢在相对安全的树上的鸟类的乞食声的区别的。然后就说到warblers 发出的乞食声的频率比在树上居住的鸟类高,传播的不如在树上的鸟类远,可以更好的隐藏这些容易受到食肉动物攻击的在地面筑巢的雏鸟。综上所述,只能选择B 选项。

Question 5 of 14


解析:我们看到DH这个人名来定位,他把人造的巢和泥土制的鸟蛋放在地上, 旁边是tape recorder,播放的是tree-nestling的乞食声或者是ground nestling warblers的乞食声,后来证明tree-nesters的乞食声导致那些eggs被咬的程度相对ground-nesters的乞食声而言更大。所以结合上文说的warblers的声音频率更高,可以得出这种高频率是一种在地面筑巢面对猎食者的一种保护机制,C选项正确。但是并没有拿frequency和声音大小做比较,所以干扰项D是不对的。

Question 6 of 14



Question 7 of 14


解析:词汇题。pinpoint精确找到,瞄准,所以B的locate exactly正确。pin大头针,point点,用大头针点当然很精确。而且原句中与pinpoint并列的是detect识别,说more evidence难以detect和什么,所以pinpoint的意思应该与detect相近。

Question 8 of 14


解析:derive“获取,获得”,所以gain正确。原句说既然begging很危险,鸟能从begging中怎么样,后面马上给出回答,说是noisy bird向父母提出精确的饥饿信号,再者证明自己身体健康,值得投喂。选择B。

Question 9 of 14


解析:问的是什么证据能证明雏鸟乞食声是获得最大利益投喂的一种指标。回归第四段和第五段内容,我们可以看到现提出一个推理理论(参见上一题),乞食声是表明饥饿的需求和健康的证明,如果这个假设成立,那么雏鸟的乞食声强度应该是随着竞争同类而调节的。Robins的例子证明,越饿的叫的越大声,然后那些不怎么饿的也把叫声变大了,虽然没有饿的叫声大。雏鸟父母也因此因为叫声强度来投放食物,喂食那些健康的。但是实际上baby swallows的实验却证明,饥饿实验组的叫声还是比定时投喂实验组的叫声大,雏鸟父母还是喂食那些乞食更为活跃的。综上所述,只有C选项正确。

Question 10 of 14


解析:上题已经分析了第四段和第五段的内容,排除法答题。A选项正好对应第四、五段实验信息的结论。其实这两段显示投喂的唯一标准就是叫声大不大而已,跟B选项喂食多少只鸟没有关系,跟C选项之前是否投喂过没有关系,跟D选项是否从巢里离开过又回来依然没有关系。注意题干是do not feed哪些鸟,反过来问的。

Question 11 of 14


解析:比较乞食叫声能量消耗和乞食叫声获得的能量摄入是为了什么。看段落第四句,明确说明这样的能量消耗和获得的能量摄入比,微不足道。但是关键是对自己同鸟类的siblings 带来伤害。

Question 12 of 14



Question 13 of 14


解析:插入句说明了两个方面,the important information to the parent和 attract the attention of others;主语是The cheeping。放在A处,前后文衔接不上,强调了转折部分:吸引注意。A处后展开例子跟attention 没多大关系。others和后面的listening hawk or raccoon刚好对应;此外B点之后的these cheeps刚好指代待插入句当中的cheeping。

Question 14 of 14


解析:Songbird species选项对应原文第二段内容,正确;Songbird parents选项对应原文第四段内容,正确;It is选项对应第六段内容,正确。













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