Vocalization in Frogs Glossary terrestrial vertebrate breed choruses
托福阅读第三篇 Vocalization in Frogs
Glossary terrestrial 地面 vertebrate 脊椎动物 breed 品种 choruses 合唱 whine 悲鸣
1 The tungara frog is a small terrestrial vertebrate that is found in Central America. (介绍一 种蛙,在中美洲)Tungara frogs breed in small pools, and breeding groups range from a single male to choruses of several hundred males. (递进,繁殖族群可能有一个可能有几百个) The advertisement call of a male tungara frog is a strange noise, a whine that starts at a frequency of 900 hertz and sweeps downward to 400 hertz in about 400 milliseconds. (递 进,介绍它通过快速变声来吸引雌性)The whine may be produced by itself, or it may be followed by one or several chucks or clucking sounds. (递进,这种声音可能是个单声,也可 能是一组音)When a male tungara frog is calling alone in a pond, it usually gives only the whine portion of the call, but as additional males join a chorus, more and more of the frogs produce calls that include chucks. (单个青蛙只会发单声,但是一群蛙就发出一串声音, 包括呱呱声)
Scientists noted that male tungara frogs calling in a breeding pond added chucks to their calls when they heard the recorded calls of other males played back. (递进,我们注意到当青 蛙听到别的雄性叫的时候,就会加入呱呱)That observation suggested that it was the presence of other calling males that incited frogs to make their calls more complex by adding chucks to the end of the whine. (递进,说明是别的雄性出现使得蛙叫声变复杂) 第一段,介绍蛙的叫声,在别的雄性蛙加入时,会变得复杂。 推测:下文要讲到加入呱呱的目的
Glossary hypothesis 理论 arena 区域 broadcast 广播
2 What advantage would a male frog in a chorus gain from using a whine-chuck call instead of a whine? (承接上一段,设问,加入呱呱的目的是什么) Perhaps the complex call is more attractive to female frogs than the simple call. (举例,可能的解释是复杂的叫声更 容易吸引雌性)Michael Ryan and Stanley Rand tested that hypothesis by placing female tungara frogs in a test arena with a speaker at each side. (做实验,我们把一只雌蛙放在一 个地方,周围有发声器)One speaker broadcast a pre-recorded whine call, and the second speaker broadcast a whine-chuck. (递进,一组放正常声音,一组放加入呱呱的)When female frogs were released individually in the center of the arena, fourteen of the fifteen frogs tested moved toward the speaker broadcasting the whine-chuck call. (结果是大多数 雌蛙都跑向加入呱呱的发声器那里) 第二段通过实验想说明复杂叫声更容易吸引雌性。
Glossary preference 偏好 expenditure 花费 vocalization 发声
3 If female frogs are attracted to whine-chuck calls in preference to whine calls, why do male frogs give whine-chuck calls only when other males are present? (反问上一段,既然 复杂叫声容易吸引雌蛙,那为什么只有当有别的蛙类存在的时候才发出复杂声音呢?)Why not always give the most attractive call possible? (递进,为什么不一直发出复杂声音呢?)One possibility is that whine-chuck calls require more energy than whines, and males save energy by only using whine-chucks when competition with other males makes the energy expenditure necessary. ( 因 果 , 一 个 可 能 解 释 是 为 了 节 省 能 量 ) However, measurements of the energy expenditure of calling male tungara frogs showed that energy cost was not related to the number of chucks. (转折,但是研究表明发出呱呱声的耗 能并不大)
Another possibility is that male frogs giving whine-chuck calls are more vulnerable to predators than frogs giving only whine calls. (并列前前句,另一种解释是发出呱呱会引来天 敌)Tungara frogs in breeding choruses are preyed upon by a species of frog-eating bats, Trachops cirrhosus, and it was demonstrated that the bats locate the frogs by homing on their vocalizations. (肯定了这种解释,因为天敌是根据蛙的发声来定位的) 第三段讲发出呱呱的可能原因,节省能量和躲避天敌。
Glossary series 系列 playback 回放 complex 复杂
4 In a series of playback experiments, Michael Ryan and Merlin Tuttle placed pairs of speakers in the forest and broadcast vocalizations of tungara frogs. (承接上一段,为了进 一步研究,做了一个实验) One speaker played a recording of a whine and the other a recording of a whine-chuck. (一组放正常的,一组放加入呱呱的)The bats responded as if the speakers were frogs: they flew toward the speakers and even landed on them. (天敌 会假想发声器就是蛙)In five experiments at different sites, the bats approached speakers broadcasting whine-chuck calls twice as frequently as those playing simple whines (168 approaches versus 81). (结果是落在呱呱组上的频率是落在正常组上的两倍)Thus, female frogs are not alone in finding whine-chuck calls more attractive than simple whines. An important predator of frogs also responds more strongly to the complex calls. (下结论, 这样说明呱呱声确实对天敌来说更有吸引力) 第四段通过一组实验来证明呱呱声对于天敌更有吸引力。
Glossary predation 捕食 choruses 副歌 consequently 结果 simultaneously 同时的 outweigh 超过
5 Ryan and his colleagues measured the rates of predation in tungara frog choruses of different sizes. Large choruses of frogs did not attract more bats than small choruses, and consequently the risk of predation for an individual frog was less in a large chorus than in a small one. (递进,又有新的研究方向了,大群落中的被捕食数量和小群落一样,说明大群落 更安全)Predation was an astonishing 19 percent of the frogs per night in the smallest chorus and a substantial 1. 5 percent per night even in the largest chorus. (举数字,不同 群落的被捕食率)【A】When a male frog shifts from a simple whine to a whine-chuck call, it increases its chances of attracting a female, but it simultaneously increases its risk of attracting a predator. (总结,当蛙发出呱呱声时,它会增加吸引雌性的概率,也会增加吸引天 敌的概率)
【B】In small choruses, the competition from other males for females is relatively small, and the risk of predation is relatively large. (递进,小群落中的雌性竞争小的,但是生存压力 大)【C】 Under these conditions it is apparently advantageous for a male tungara frog to give simple whines. (总结,这样看来,只发出正常声音是最好的)【D】However, as chorus size increases, competition with other males also increases while the risk of predation falls. (然后,随着群落数量变大,竞争变大但是危险变小)In that situation, the advantage of giving a complex call apparently outweighs the risks. (总结,这是发出呱呱声 是最好的) 第五段分析了不同群落里的竞争优势和危险系数。
1 The word incited in the passage is closest in meaning to A. allowed B. stimulated C. forced D. helped A允许 B刺激 C 强加 D帮助 incite是刺激的意思,选B.
2 According to paragraph 1, male tungara frogs add chucks to the whine they produce when. A. potential mates are unable to hear the frequency of their whine sounds B. other males produce louder whine sounds than they do C. the frogs breed in large pools rather than small ones D. other males are present in their breeding pool additional males join a chorus, more and more of the frogs produce calls that include chucks,当有别的雄性加入的时候,就会发出呱呱声,选D.
3 What is the relationship of paragraph 2 in the passage to paragraph 1. A. Paragraph 2 provides additional support for a scientific hypothesis discussed in paragraph 1. B. Paragraph 2 questions the accuracy of a scientific observation discussed in paragraph 1. C. Paragraph 2 provides a possible explanation for a scientific observation discussed in paragraph 1. D. Paragraph 2 identifies some strengths and weaknesses of a scientific hypothesis discussed in paragraph 1. 第一段讲现象,第二段讲解释,选C.
4 According to paragraph 2, Ryan and Rand conducted an experiment to find out whether which of the following theories was true. A. Male frogs in a chorus use a whine-chuck call in place of a whine call. B. Female frogs prefer a whine-chuck call to a simple whine call. C. Male frogs tend to produce more whine-chuck calls than whine calls. D. Female frogs respond differently to live calls from males than they do to recorded calls. Perhaps the complex call is more attractive to female frogs than the simple cal, 做实验的目的是想知道加入呱呱声是否会有更大的吸引力,选B.
5 To be attracted to whine-chuck calls in preference to whine calls means A. to like whine-chuck calls instead of whine calls B. to like whine-chuck calls in addition to whine calls C. to like whine-chuck calls followed by whine calls D. to like whine-chuck calls more than whine calls 句意理解,是说相比whine 更喜欢whine-chuck,选D.
6 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. One possibility is that whine-chuck calls require more energy than whines, and males save energy by only using whine-chucks when competition with other males makes the energy expenditure necessary. A. Males may save energy when competing for mates by using only whine-chuck calls rather than both whines and whine-chucks. B. Males expend as much of their energy on whine-chuck calls as on whine calls when competing with other males.
C. Males save energy by using whine-chuck calls only when competing with other males. D. Males that save energy by using only whines are less able to compete with other males. 加黑句的意思是说whine需要的能量少,当有别的雄性时, 这种能量花费是必需的,选C.
7 According to paragraph 4, all of the following are true of the playback experiments EXCEPT: A. Female frogs and predator bats approached the broadcasting speakers. B. The bats responded more strongly to the whine-chuck calls than they responded to the whine calls. C. Each speaker played a different kind of male frog call. D. The same experiment was repeated at different locations. 没有放入雌蛙,选A.
8 According to paragraph 4, the playback experiments of Ryan and Tuttle demonstrated which of the following. A. Tungara frogs use both whines and whine-chucks in their vocalizations. B. Female tungara frogs are attracted to both whine and whine-chuck vocalizations. C. Female tungara frogs and predators of tungara frogs are attracted to different types of vocalizations. D. Frog-eating bats are attracted to whine-chuck calls more than to whines alone. An important predator of frogs also responds more strongly to the complex calls, 根据第四段,实验表明天敌对呱呱声更喜欢,选D.
9 The word substantial in the passage is closest in meaning to A. average B. smaller C. considerable D. surprising A平均 B更小 C大量的 D惊讶的 substantial 指大量的,选C.
10 The word outweighs in the passage is closest in meaning to A. exceeds B. ignores C. minimizes D. disguises A超过 B忽略 C最小 D伪装 outweigh是超过的意思,选A.
11 According to paragraph 5, all of the following are true about tungara frog vocalizations EXCEPT: A. The larger the frog chorus, the smaller the chance there is of a particular frog being eaten by a predatory bat. B. The larger the frog chorus, the louder each individual frog calls. C. The smaller the frog chorus, the easier it is for a frog to attract a female. D. The smaller the frog chorus, the more likely it becomes that a frog using the whine -chuck vocalization will be attacked by a bat. 没提到群落越大,声音越大,选B.
12 Which of the following can be inferred from paragraph 5 about the behavior of male tungara frogs. A. When in small choruses they use less effective mating calls to decrease their risk of predation. B. They avoid joining a large chorus in a breeding pool because it increases the risk of predation. C. They avoid the use of the whine-chuck call whenever there is the risk of predators. D. They attempt to avoid predation by making their calls at night. 在小群落中,会使用正常声音,因为不危险,选A.
13 Look at the four squares that indicate where the following sentence could be added to the passage. Predation, therefore, is a risk in choruses of all sizes, but the risk varies depending on the type of call used. Where would the sentence best fit? Click on a square to add the sentence to the passage. 插入句表示被捕食的危险都存在,但是在不同大小的群落中不一样, 说明后面要讲不同大小下的不同情况,前面要讲predation,选A.
14 Drag your choices to the spaces where they belong. To review the passage, click on View Text. A Tungara frogs generally use simple calls when they wish to attract a mate, and complex calls when they wish to avoid predation. (不是说蛙在想吸引异性是就用正常声音,想躲避危险就呱呱,逻辑错。) B Two hypotheses have been put forward about why females and frog-eating bats are more attracted to males using whine-chuck calls. (只有一种理论,就是呱呱声对于雌性和天敌更有吸引力,没有两种,内容错。) C The hypothesis that whine calls are used to save energy when males are not in immediate competition with each other has been disproved by showing that chuck calls do not require more energy. (正常发音没有比呱呱更耗费能量,否定了假说,正确。)
D Tungara females overwhelmingly favor the whine-chuck call used by the males, but so do certain bats that prey upon tungara frogs. (雌性蛙和天敌都是对呱呱声更有兴趣,正确。) E Most males gather in groups of several hundreds when calling because the rate of predation from bats is so high in small groups. (蛙聚集起来的目的是小群落中的危险高,但是不管大群落还是小群落,天敌的攻击 次数都是差不多的,内容错。) F Male tungara frogs use the whine-chuck call in large groups, where their risk of predation is lower, and the whine call in small groups, where their risk is higher. (蛙在大群落中呱呱叫,因为危险小,在小群落中正常叫,因为危险高,正确。) C D F
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