『新东方在线托福阅读』为托福考生准备了ETS托福TPO/Official 30 Passage 1阅读练习：Why does the author include the comment “though they were fed the same diets”?真题题目及答案解析，TPO/Official 30 Passage 1阅读原文范文音频翻译

托福TPO/Official 30 Passage 1阅读原文Why does the author include the comment “though they were fed the same diets”?题目答案及解析-新东方托福官方网校手机版

用例子比用概念更容易定义玩耍。

Play is easier to define with examples than with concepts.

无论如何，在动物中，它包括跳跃、奔跑、攀爬、投掷、摔跤和其他动作，或者单独，或者与物体，或者与其他动物。

In any case, in animals it consists of leaping, running, climbing, throwing, wrestling, and other movements, either alone, with objects, or with other animals.

根据物种的不同，玩耍可能主要是为了社交、锻炼或探索。

Depending on the species, play may be primarily for social interaction, exercise, or exploration.

要给玩耍下一个明确的定义，其中的一个问题是，它所涉及的行为与在支配、捕食、竞争和真正的战斗等其他情况下的行为是一样的。

One of the problems in providing a clear definition of play is that it involves the same behaviors that take place in other circumstances – dominance, predation, competition, and real fighting.

因此，玩耍是否发生取决于动物的意图，而且意图仅从行为上判断不总是明确的。

Thus, whether play occurs or not depends on the intention of the animal, and intentions are not always clear from behavior alone.

玩耍似乎是具有相当复杂的神经系统的动物（主要是鸟类和哺乳动物）的一种发育特征。

Play appears to be a developmental characteristic of animals with fairly sophisticated nervous systems, mainly birds and mammals.

玩耍在灵长类和犬科动物（狗）中被广泛研究。

Play has been studied most extensively in primates and canids (dogs).

究竟为什么动物会玩耍，在研究文献中仍是一个有争议的问题，而原因可能对每一个会玩耍的物种来说都是不同的。

Exactly why animals play is still a matter debated in the research literature, and the reasons may not be the same for every species that plays.

确定玩耍的功能是困难的，因为这些功能可能是长期的，有益的影响要到动物成年后才会显现。

Determining the functions of play is difficult because the functions may be long-term, with beneficial effects not showing up until the animal’s adulthood.

玩耍对单个动物来说并非没有一定代价。

Play is not without considerable costs to the individual animal.

玩耍通常是非常活跃的，包括在空间中的运动，有时还包括制造噪音。

Play is usually very active, involving movement in space and, at times, noisemaking.

因此，它会导致能量的损失，而这些能量可以更好地用于幼畜的生长或积存脂肪。

Therefore, it results in the loss of fuel or energy that might better be used for growth or for building up fat stores in a young animal.

这种行为的另一个潜在代价是更大程度地暴露在捕食者面前，因为玩耍是获得注意力的行为。

Another potential cost of this activity is greater exposure to predators since play is attention-getting behavior.

更多的活动也会增加在滑倒或跌倒时受伤的风险。

Greater activity also increases the risk of injury in slipping or falling.

根据达尔文的理论，玩耍的好处一定大于代价，否则玩耍行为就不会产生。

The benefits of play must outweigh the costs, or play would not have evolved, according to Darwin’s theory.

一些潜在的好处与大脑和神经系统的健康发展直接相关。

Some of the potential benefits relate directly to the healthy development of the brain and nervous system.

在一项研究中，两组幼鼠在不同的条件下被饲养。

In one research study, two groups of young rats were raised under different conditions.

一组老鼠在“富足”的环境中成长，这使得老鼠可以与其他老鼠互动，玩玩具，并接受迷宫训练。

One group developed in an “enriched” environment, which allowed the rats to interact with other rats, play with toys, and receive maze training.

另一组生活在“贫困”的环境中，在单独的笼子里，在光线昏暗、几乎没有刺激的房间里。

The other group lived in an “impoverished” environment in individual cages in a dimly lit room with little stimulation.

实验结束时，结果显示，贫困老鼠的大脑实际重量比富足环境中的老鼠要轻（尽管它们吃的是同样的食物）。

At the end of the experiments, the results showed that the actual weight of the brains of the impoverished rats was less than that of those raised in the enriched environment (though they were fed the same diets).

其他研究表明，更大的刺激不仅会影响大脑的大小，还会增加神经细胞之间的连接数量。

Other studies have shown that greater stimulation not only affects the size of the brain but also increases the number of connections between the nerve cells.

因此，积极的玩耍可能为大脑突触连接的生长提供必要的刺激，尤其是小脑，它负责运动功能和运动。

Thus, active play may provide necessary stimulation to the growth of synaptic connections in the brain, especially the cerebellum, which is responsible for motor functioning and movements.

玩耍还能刺激肌肉组织的发育，并为生存所需的动作提供锻炼的机会。

Play also stimulates the development of the muscle tissues themselves and may provide the opportunity to practice those movements needed for survival.

猎物如小鹿或山羊，通常通过突然的飞行动作和转弯来进行游戏，而食肉动物，如猫，则练习跟踪、突袭和撕咬。

Prey species, like young deer or goats, for example, typically play by performing sudden flight movements and turns, whereas predator species, such as cats, practice stalking, pouncing, and biting.

玩耍可以让小动物在相对安全的环境中探索和练习技能，因为周围的成年动物通常不指望小动物能应付威胁或捕食者。

Play allows a young animal to explore its environment and practice skills in comparative safety since the surrounding adults generally do not expect the young to deal with threats or predators.

玩耍还可以为求爱和交配所需的社会行为提供练习。

Play can also provide practice in social behaviors needed for courtship and mating.

学习适当的社会行为在群居的物种中尤其重要，就像年轻的猴子需要学习控制自私和攻击性，并理解社会群体中的相互迁就。

Learning appropriate social behaviors is especially important in species that live in groups, like young monkeys that need to learn to control selfishness and aggression and to understand the give-and-take involved in social groups.

他们需要学习如何主导和服从，因为每只猴子可能在未来扮演任何一个角色。

They need to learn how to be dominant and submissive because each monkey might have to play either role in the future.

大多数这些东西都是在灵长类动物漫长的发育过程中习得的，在这一过程中，它们会与同伴进行无数次的玩耍体验。

Most of these things are learned in the long developmental periods that primates have, during which they engage in countless play experiences with their peers.

当然，有一种危险是，玩耍可能被他人误解或不被别人认可，从而潜在地导致攻击性。

There is a danger, of course, that play may be misinterpreted or not recognized as play by others, potentially leading to aggression.

当玩耍包括练习正常的攻击性或捕食者行为时，这一点尤其真实。

This is especially true when play consists of practicing normal aggressive or predator behaviors.

因此，许多物种已经进化出清晰的信号来表达玩耍。

Thus, many species have evolved clear signals to delineate playfulness.

例如，狗会摇尾巴，放低前腿，把屁股翘起来，表示“接下来的动作只是为了好玩”。

Dogs, for example, will wag their tails, get down their front legs, and stick their behinds in the air to indicate "what follows is just for play."

According to paragraph 1, why is play difficult to define?

According to paragraph 2, which of the following presents a particular challenge to researchers who study play behavior in animals?

According to paragraph 3, each of the following is a cost to animals that engage in play EXCEPT

Why does the author include the comment “though they were fed the same diets”?

According to paragraph 5, why might play behaviors of prey species be different from those of predator species?

The word “comparative” in the passage is closest in meaning to

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.

What can be inferred from paragraph 6 about the role of adults in play activities of the young?

Look at the four squares  that indicate where the following sentence could be added to the passage. With messages such as those, even dogs that are strangers to each other can be playing within a few minutes.  Where would the sentence best fit? Click on a square  to add the sentence to the passage.

Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.

Role of Play in Development Play is easier to define with examples than with concepts. In any case, in animals it consists of leaping, running, climbing, throwing, wrestling, and other movements, either alone, with objects, or with other animals. Depending on the species, play may be primarily for social interaction, exercise, or exploration. One of the problems in providing a clear definition of play is that it involves the same behaviors that take place in other circumstances – dominance, predation, competition, and real fighting. Thus, whether play occurs or not depends on the intention of the animal, and intentions are not always clear from behavior alone. Play appears to be a developmental characteristic of animals with fairly sophisticated nervous systems, mainly birds and mammals. Play has been studied most extensively in primates and canids (dogs). Exactly why animals play is still a matter debated in the research literature, and the reasons may not be the same for every species that plays. Determining the functions of play is difficult because the functions may be long-term, with beneficial effects not showing up until the animal’s adulthood. Play is not without considerable costs to the individual animal. Play is usually very active, involving movement in space and, at times, noisemaking. Therefore, it results in the loss of fuel or energy that might better be used for growth or for building up fat stores in a young animal. Another potential cost of this activity is greater exposure to predators since play is attention-getting behavior. Greater activity also increases the risk of injury in slipping or falling. The benefits of play must outweigh the costs, or play would not have evolved, according to Darwin’s theory. Some of the potential benefits relate directly to the healthy development of the brain and nervous system. In one research study, two groups of young rats were raised under different conditions. One group developed in an “enriched” environment, which allowed the rats to interact with other rats, play with toys, and receive maze training. The other group lived in an “impoverished” environment in individual cages in a dimly lit room with little stimulation. At the end of the experiments, the results showed that the actual weight of the brains of the impoverished rats was less than that of those raised in the enriched environment (though they were fed the same diets). Other studies have shown that greater stimulation not only affects the size of the brain but also increases the number of connections between the nerve cells. Thus, active play may provide necessary stimulation to the growth of synaptic connections in the brain, especially the cerebellum, which is responsible for motor functioning and movements. Play also stimulates the development of the muscle tissues themselves and may provide the opportunity to practice those movements needed for survival. Prey species, like young deer or goats, for example, typically play by performing sudden flight movements and turns, whereas predator species, such as cats, practice stalking, pouncing, and biting. Play allows a young animal to explore its environment and practice skills in comparative safety since the surrounding adults generally do not expect the young to deal with threats or predators. Play can also provide practice in social behaviors needed for courtship and mating. Learning appropriate social behaviors is especially important in species that live in groups, like young monkeys that need to learn to control selfishness and aggression and to understand the give-and-take involved in social groups. They need to learn how to be dominant and submissive because each monkey might have to play either role in the future. Most of these things are learned in the long developmental periods that primates have, during which they engage in countless play experiences with their peers. There is a danger, of course, that play may be misinterpreted or not recognized as play by others, potentially leading to aggression.  This is especially true when play consists of practicing normal aggressive or predator behaviors.  Thus, many species have evolved clear signals to delineate playfulness.  Dogs, for example, will wag their tails, get down their front legs, and stick their behinds in the air to indicate "what follows is just for play."