小伙伴们，老沉老沉的干货又来啦！大家还记得我们上次在2017托福阅读考情分析中对学科做出的统计吗？来，敲黑板，划个重点~

　　在这122篇生物类文章中，有23篇都是关于鸟的话题，也就是说几乎平均每两场就有一篇要和鸟打交道，比如Bird Colonies，The origin of flight of birds，How Birds Acquire Their Songs，Birdsong等。

　　其中，Birdsong是2015.1.11的老题，2016.3.26重复过一次，17年更是在6.3/ 12.9/ 12.10重复了三次。

　　今天咱们就把这篇原汁原味的考场原题和大家一起分享。另外，段落结构切分的地方小编都用//标出来了，方便大家整体把握文章框架。还附有这篇的参考答案。

　　Ready？Go！

　　Birdsong

　　Birdsong is the classic example of how genes (hereditary information) and environment both have a crucial role to play in the behavioral development of animals. Since the pioneering work of W. H. Thorpe on chaffinches (a common European bird), many species have been studied, and it has become clear both that learning plays an important role for all species and also that there are constraints on what they are able to learn.

　　Thorpe was able to show that learning from others was involved in chaffinch birds through a series of experiments on hand-reared chicks (young birds). As in most other species, only the males sing. Thorpe found that, if he raised young males in total isolation from all others, the song they produced was quite different from that of a normal adult. It was about the right length and in the correct frequency range, it was also split up into a series of notes as it should be. But these notes lacked the detailed structure found in wild birds, nor was the song split up into distinct phrases as it usually is. This suggested that song development requires some social influence. Later experiments in which researchers played recordings of songs to young birds showed just how precise this influence was, many of them would learn the exact pattern of the recording they had heard. A remarkable feature here was in the first few weeks of life, yet they did not sing themselves until about eight months old. They are thus able to store a memory of the sound within their brain and then match their own output to their collection of it when they mature.

　　Young chaffinches normally learn only chaffinch song, though Thorpe found they could be trained to sing the song of a tree pipit (another type of bird), which is very similar to that of their own species. In general, however, the constraints on learning which birds have ensure that they only learn songs appropriate to the species to which they themselves belong. These constraints may be in their brain’s circuitry, the young bird hatching with a rough idea of the sounds that it should copy. The crude song of a bird reared in isolation gives some clues as to what this rough idea may be the length, the frequency range, and the breaking up into notes are all aspects of chaffinch song shared between normal birds and those reared in isolation. In other cases, the constraints are more social, young birds only being prepared to learn from individuals with whom they have social interactions. Thus, in a number of species, it has been found that they will not copy from recordings, but will do so from a live tutor. In some cases, this may occur when they are young birds, but in others the main learning period is when they set up their territories and interact with neighbors for the first time, enabling them to match their neighbor’s songs and so countering with them. Whatever the nature of the learning rules in a particular species, there is no doubt that they are effective, it is very unusual to hear a wild bird singing a song which is not typical of its own species despite the many different songs which often occur in a small patch of woodland.

　　However, not all birds show the same learning pattern as do chaffinches. There are some species which produce normal sounds even if deaf, so that they cannot hear their own efforts, much less copy those of others. The cooing of doves and the crowing of cocks are examples here. In other cases, such as parrots and hill mynahs, birds can be trained to copy a huge variety of sounds, though those they learn in the wild are usually more restricted. The amazing capability of mynahs has apparently arisen simply because birds in an area learn a small number of their calls from each other, males from males and females from females, and these calls are highly varied in structure. The ability to master them has led the birds, incidentally, to be capable of saying “hello” and mimicking a wide variety of other sounds.

　　Directions:Now answer the questions.

　　Paragraph 1: Birdsong is the classic example of how genes (hereditary information) and environment both have a crucial role to play in the behavioral development of animals. Since the pioneering work of W. H. Thorpe on chaffinches (a common European bird), many species have been studied, and it has become clear both that learning plays an important role for all species and also that there are constraints on what they are able to learn.

　　1. The word pioneering in the passage is closest in meaning to

　　A. recent

　　B. famous

　　C. original

　　D. controversial

　　Paragraph 2: Thorpe was able to show that learning from others was involved in chaffinch birds through a series of experiments on hand-reared chicks (young birds). As in most other species, only the males sing（Q5-D）. Thorpe found that, if he raised young males in total isolation from all others, the song they produced was quite different from that of a normal adult（Q3-A）. It was about the right length and in the correct frequency range（Q3-C）, it was also split up into a series of notes as it should be. But these notes lacked the detailed structure found in wild birds（Q3-B）, nor was the song split up into distinct phrases as it usually is. This suggested that song development requires some social influence.（Q5-B） // Later experiments in which researchers played recordings of songs to young birds showed just how precise this influence was, many of them would learn the exact pattern of the recording they had heard（Q5-A）. A remarkable feature here was in the first few weeks of life, yet they did not sing themselves until about eight months old. They are thus able to store a memory of the sound within their brain and then match their own output to their collection of it when they mature.（Q4出题句）

　　2. The word distinct in the passage is closest in meaning to

　　A. short

　　B. simple

　　C. separate

　　D. similar

　　3. According to paragraph 2, all of the following are characteristics of the songs of the young chaffinches in Thorpe’s experiment EXCEPT:

　　A. They were not identical to the songs of normal adult chaffinches.

　　B. They lacked the complex form of the songs of wild chaffinches.

　　C. They were as long as the songs of normal adult chaffinches.

　　D. They were clearly different from each other.

　　4. According to paragraph 2, researchers discovered which of the following by playing recordings of songs to chaffinches?

　　A. Chaffinches could no longer be taught to reproduce sounds after the first few weeks of life.

　　B. Chaffinches could not reproduce songs with exactly the same patterns of recorded songs.

　　C. Chaffinches at the age of eight months could recall and reproduce a song that they heard in the first few weeks of life.

　　D. Chaffinches that learned a song from recordings in the first few weeks of life were later unable to copy the sounds of mature chaffinches.

　　5. All of the following are mentioned in paragraph 2 as characteristic of wild chaffinches EXCEPT:

　　A. They are able to copy songs very precisely.

　　B. Their song development requires interaction with other chaffinches.

　　C. Their songs are not as well-structured as the songs of other birds.

　　D. It is the males of the species that do the singing.

　　Paragraph 3: Young chaffinches normally learn only chaffinch song, though Thorpe found they could be trained to sing the song of a tree pipit (another type of bird), which is very similar to that of their own species. ■ In general, however, the constraints on learning which birds have ensure that they only learn songs appropriate to the species to which they themselves belong. ■// These constraints may be in their brain’s circuitry, the young bird hatching with a rough idea of the sounds that it should copy. ■The crude song of a bird reared in isolation gives some clues as to what this rough idea may be the length, the frequency range and the breaking up into notes are all aspects of chaffinch song shared between normal birds and those reared in isolation. ■// In other cases the constraints are more social, young birds only being prepared to learn from individuals with whom they have social interactions（Q9出题句）. Thus, in a number of species, it has been found that they will not copy from recordings, but will do so from a live tutor. In some cases, this may occur when they are young birds, but in others the main learning period is when they set up their territories and interact with neighbors for the first time, enabling them to match their neighbor’s songs and so countering with them (Q7出题句). Whatever the nature of the learning rules in a particular species, there is no doubt that they are effective (Q10出题句); it is very unusual to hear a wild bird singing a song which is not typical of its own species despite the many different songs which often occur in a small patch of woodland.

　　6. The word enabling in the passage is closest in meaning to

　　A. allowing

　　B. challenging

　　C. forcing

　　D. preparing

　　7. It can be inferred from paragraph 3 that one of the functions of songs in birds is to

　　A. bring together birds living in groups with birds living in isolation

　　B. help young birds distinguish other young birds from adults

　　C. make possible interactions between birds of different species

　　D. help birds to establish territories

　　8. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.

　　A. Songs produced by chaffinches reared in isolation are cruder than the songs of wild birds.

　　B. The song of a bird reared in isolation suggests which aspects of chaffinch song may be inborn.

　　C. Comparing the crude songs of chaffinches reared in isolation to the songs of wild chaffinches suggests differences as well as similarities.

　　D. By studying the song aspects of chaffinches reared in isolation, researchers have gained a better understanding of the songs produced by wild birds.

　　9. According to paragraph 3, in some species, young birds do not copy songs from recordings because

　　A. they learn to sing only by live interactions with other birds

　　B. their ability to learn from recordings occurs later in life

　　C. they can only learn songs from the birds living in their area of woodland

　　D. they can only learn songs from other birds of their own species

　　10. Why does the author mention that it is very unusual to hear a wild bird singing a song which is not typical of its own species?

　　A. To explain why a variety of different bird songs are often heard in a relatively small area

　　B. To argue that social constraints have a greater impact upon learning than do genetic constraints

　　C. To provide an example of how the process of learning rules varies from one species to another

　　D. To illustrate how effective the different constraints upon learning are in young birds

　　Paragraph 4: However, not all birds show the same learning pattern as do chaffinches. There are some species which produce normal sounds even if deaf, so that they cannot hear their own efforts, much less copy those of others. The cooing of doves and the crowing of cocks are examples here. //In other cases, such as parrots and hill mynahs, birds can be trained to copy a huge variety of sounds, though those they learn in the wild are usually more restricted. The amazing capability of mynahs has apparently arisen simply because birds in an area learn a small number of their calls from each other, males from males and females from females, and these calls are highly varied in structure (Q12出题句). The ability to master them has led the birds, incidentally, to be capable of saying “hello” and mimicking a wide variety of other sounds.

　　11. The word restricted in the passage is closest in meaning to

　　A. important

　　B. popular

　　C. limited

　　D. accurate

　　12. According to paragraph 4, why are mynahs able to learn to make a wide variety of sounds?

　　A. They have the ability to imitate any sound that they are exposed to

　　B. The frequency with which mynahs travel from one small area to another exposes them to a wide variety of sounds.

　　C. They are exposed in the wild to calls that are very different from each other.

　　D. An acute sense of hearing allows them to listen to and copy many different sounds.

　　Paragraph 3: Young chaffinches normally learn only chaffinch song, though Thorpe found they could be trained to sing the song of a tree pipit (another type of bird), which is very similar to that of their own species. ■ In general, however, the constraints on learning which birds have ensure that they only learn songs appropriate to the species to which they themselves belong. ■ These constraints may be in their brain’s circuitry, the young bird hatching with a rough idea of the sounds that it should copy. ■ The crude song of a bird reared in isolation gives some clues as to what this rough idea may be the length, the frequency range, and the breaking up into notes are all aspects of chaffinch song shared between normal birds and those reared in isolation. ■ In other cases, the constraints are more social, young birds only being prepared to learn from individuals with whom they have social interactions. Thus, in a number of species, it has been found that they will not copy from recordings, but will do so from a live tutor. In some cases, this may occur when they are young birds, but in others the main learning period is when they set up their territories and interact with neighbors for the first time, enabling them to match their neighbor’s songs and so countering with them. Whatever the nature of the learning rules in a particular species, there is no doubt that they are effective, it is very unusual to hear a wild bird singing a song which is not typical of its own species despite the many different songs which often occur in a small patch of woodland.

　　13. Look at the four squares [■] that indicate where the following sentence could be added to the passage.

　　Are these constraints genetic, environmental, or both?

　　14. Directions: An introductory sentence for a brief summary of the passage is provided below.

　　A combination of hereditary and environmental factors is believed to determine the sounds that birds are able to produce.

　　A. Although only male chaffinches are able to sing in the wild, Thorpe found that he could teach hand-reared females to copy songs from recordings and live tutors.

　　B. Chaffinches reared in isolation produce songs that differ significantly from those of normal birds, suggesting that some social influence is important for learning a song precisely.

　　C. Birds vary a great deal with respect to both the variety of sounds they are able to learn and the conditions that must be present for them to be able to learn their species’ song.

　　D. Chaffinches that are exposed only to other bird species for the first few weeks of their life are likely to learn the songs of those species instead of the chaffinch song.

　　E. Researchers believe that both the circuitry or a bird’s brain and its interactions with other birds of the same species may prevent birds from learning the songs of other species.

　　F. The ability of deaf birds to produce their normal species’ song suggests that genes play a much greater role than environment in determining the behavior of most bird species.

　　参考答案：CCDCC ADBAD CCB BCE

　　作者简介：蒋琳琳

　　济南新航道耶鲁SVIP阅读讲师

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