『新东方在线托福阅读』为托福考生准备了ETS托福TPO/Official 40 Passage 3阅读练习：Why does the author mention a “South American frog” species in the passage?真题题目及答案解析，TPO/Official 40 Passage 3阅读原文范文音频翻译

托福TPO/Official 40 Passage 3阅读原文Why does the author mention a “South American frog” species in the passage?题目答案及解析-新东方托福官方网校手机版

与哺乳动物和鸟类不同，两栖动物无法通过新陈代谢活动产生热能，这种活动使哺乳动物和鸟类能够独立于周围或环境温度来调节体温。

In contrast to mammals and birds, amphibians are unable to produce thermal energy through their metabolic activity, which would allow them to regulate their body temperature independent of the surrounding or ambient temperature.

然而，两栖动物无法控制其体温的观点已经被证明是错误的，因为它们的体温并不总是与周围的温度相对应。

However, the idea that amphibians have no control whatsoever over their body temperature has been proven false because their body temperature does not always correspond to the surrounding temperature.

虽然两栖动物的体温调节能力很差，但它们确实能在有限的程度上控制自己的体温。

While amphibians are poor thermoregulators, they do exercise control over their body temperature to a limited degree.

生理适应可以帮助两栖动物在极端条件盛行的栖息地定居。

Physiological adaptations can assist amphibians in colonizing habitats where extreme conditions prevail.

体温的耐受范围代表了一个物种能够生存的温度范围。

The tolerance range in body temperature represents the range of temperatures within which a species can survive.

当温度下降到零下2摄氏度时，一种北美蝾螈仍然活跃，而一种南美青蛙即使温度上升到41摄氏度——这是在自由放养的两栖动物中测得的最高体温——也感觉很舒服。

One species of North American newt is still active when temperatures drop to -2ºC while one South American frog feels comfortable even when temperatures rise to 41ºC—the highest body temperature measured in a free-ranging amphibian.

最近有研究表明，一些北美青蛙和蟾蜍物种在体温为零下6摄氏度，大约三分之一的体液被冷冻的情况下，可以存活长达5天。

Recently it has been shown that some North American frog and toad species can survive up to five days with a body temperature of -6ºC with approximately one-third of their body fluids frozen.

其他组织受到保护，因为它们含有防冻剂甘油或葡萄糖。

The other tissues are protected because they contain the frost-protective agents glycerin or glucose.

此外，在许多物种中，耐受边界是灵活的，可以随着驯化（长期暴露在特定条件下）而改变。

Additionally, in many species the tolerance boundaries are flexible and can change as a result of acclimatization (long-term exposure to particular conditions).

尽管白天温度很高，但仍暴露在阳光下的青蛙物种在皮肤结构上表现出一些令人着迷的变化，这些变化起到了形态适应的作用。

Frog species that remain exposed to the sun despite high diurnal (daytime) temperatures exhibit some fascinating modifications in the skin structure that function as morphological adaptations.

大多数两栖动物的皮肤是完全透水的，因此不能成为阻挡蒸发或太阳辐射的屏障。

Most amphibian skin is fully water permeable and is therefore not a barrier against evaporation or solar radiation.

非洲稀树草原蛙金丝桃蛙的皮肤中储存了鸟嘌呤晶体，这使它能够更好地反射太阳辐射，从而提供防止过热的保护。

The African savanna frog Hyperolius viridiflavus stores guanine crystals in its skin, which enable it to better reflect solar radiation, thus providing protection against overheating.

腊白猴树蛙对蒸发损失的反应是通过腺体分泌物在整个身体上提供一层油腻的薄膜，帮助防止干燥（脱水）。

The tree frog Phyllomedusa sauvagei responds to evaporative losses with gland secretions that provide a greasy film over its entire body that helps prevent desiccation (dehydration).

然而，到目前为止，行为是体温调节中最重要的因素。

However, behavior is by far the most important factor in thermoregulation.

行为体温调节的主要因素是晒太阳（日温），与岩石或泥土等底物的热交换（西格玛），以及白天和每年的回避行为，包括白天移动到避难所降温、冬眠或避暑（分别在寒冷或炎热天气减少活动）。

The principal elements in behavioral thermoregulation are basking (heliothermy), heat exchange with substrates such as rock or earth (thigmothermy), and diurnal and annual avoidance behaviors, which include moving to shelter during the day for cooling and hibernating or estivating (reducing activity during cold or hot weather, respectively).

日温在青蛙和蟾蜍中尤其常见：它可以让它们的体温提高10摄氏度以上。

Heliothermy is especially common among frogs and toads: it allows them to increase their body temperature by more than 10ºC.

安第斯蟾蜍在日出后立即暴露在潮湿的地面上，并通过这种方式达到它喜欢的体温，这远早于地面或空气相应的升温。

The Andean toad Bufo spinulosusexposes itself immediately after sunrise on moist ground and attains its preferred body temperature by this means, long before either ground or air is correspondingly warmed.

这种方法的一个积极的副作用是，它加速了一夜之间被吃掉的猎物的消化，因此也加速了生长。

A positive side effect of this approach is that it accelerates the digestion of the prey consumed overnight, thus also accelerating growth.

虽然挤压地面上有双重目的：通过传导性吸收热量和通过皮肤吸收水分，但大多数两栖动物都有西格玛这种行为。

Thigmothermy is a behavior present in most amphibians, although pressing against the ground serves a dual purpose: heat absorption by conductivity and water absorption through the skin.

在降雨期间，西格玛效应在安第斯蟾蜍身上表现得尤为明显：它的体温与温暖的地表温度相对应，而不是与低得多的空气温度相对应。

The effect of thigmothermy is especially evident in the Andean toad during rainfall: its body temperature corresponds to the temperature of the warm earth and not to the much cooler air temperature.

每当生理和形态适应不足以将体温维持在生命范围内时，就会出现回避行为。

Avoidance behavior occurs whenever physiological and morphological adaptations are insufficient to maintain body temperature within the vital range.

对环境温度耐受性低的两栖动物的夜间活动是一种典型的回避体温调节行为。

Nocturnal activity in amphibians with low tolerance for high ambient temperatures is a typical thermoregulatory behavior of avoidance.

季节性回避行为在许多两栖动物中是极其重要的。

Seasonal avoidance behavior is extremely important in many amphibians.

栖息地位于温带的物种在冬季面临致命的低温，而居住在干旱和半干旱地区的物种在夏季面临长时间的干旱和炎热。

Species whose habitat lies in the temperate latitudes are confronted by lethal low temperatures in winter, while species dwelling in arid and semi-arid regions are exposed to long dry, hot periods in summer.

在两栖动物中，冬眠发生在泥土中或远离霜冻的深洞里。

In amphibians hibernation occurs in mud or deep holes away from frost.

比利牛斯山脉以北的纳特杰克蟾蜍是冬眠的一个很好的例子，它在深挖到沙地里的地方过冬。

North of the Pyrenees Mountains, the natterjack toad offers a good example of hibernation, passing the winter dug deep into sandy ground.

相反，西班牙南部的纳特杰克蟾蜍在该地区常见的暖冬期间仍然活跃，而在干燥炎热的夏季被迫不活动。

Conversely, natterjacks in southern Spain remain active during the mild winters common to the region and are instead forced into inactivity during the dry, hot summer season.

为了避免干燥和致命的环境温度，夏眠也通过在地下挖洞或躲在凉爽的深岩石裂缝中进行。

Summer estivation also occurs by burrowing into the ground or hiding in cool, deep rock crevasses to avoid desiccation and lethal ambient temperatures.

因此，两栖动物几乎不受环境温度的支配，因为通过上述机制，它们能够对自己的体温进行一定程度的控制。

Amphibians are therefore hardly at the mercy of ambient temperatures, since by means of the mechanisms described above they are more than able to exercise some control over their body temperature.

According to paragraph 1, what indicates that amphibians have some control over their body temperature?

Why does the author mention a “South American frog” species in the passage?

According to paragraph 2, what allows some North American frog and toad species to survive in ambient temperatures well below freezing?

“Phyllomedusa sauvagei” is mentioned as an example of a frog with an adaptation that

Paragraph 4 mentions each of the following as an example of behavioral thermoregulation EXCEPT

The “Andean toad Bufo spinulosus” illustrates which of the following behavioral modifications?

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

The phrase “this approach” in the passage refers to

According to paragraph 5, why is avoidance behavior important for some amphibians?

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

In paragraph 6, which of the following can be inferred from the discussion of the natterjack?

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.

Look at the four squares  that indicate where the following sentence could be added to the passage. On the other hand, amphibians in very hot climates use secretions from the mucus glands to decrease their temperature through evaporative cooling on the skin.  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.

Amphibian Thermoregulation In contrast to mammals and birds, amphibians are unable to produce thermal energy through their metabolic activity, which would allow them to regulate their body temperature independent of the surrounding or ambient temperature. However, the idea that amphibians have no control whatsoever over their body temperature has been proven false because their body temperature does not always correspond to the surrounding temperature. While amphibians are poor thermoregulators, they do exercise control over their body temperature to a limited degree. Physiological adaptations can assist amphibians in colonizing habitats where extreme conditions prevail. The tolerance range in body temperature represents the range of temperatures within which a species can survive. One species of North American newt is still active when temperatures drop to -2ºC while one South American frog feels comfortable even when temperatures rise to 41ºC—the highest body temperature measured in a free-ranging amphibian.  Recently it has been shown that some North American frog and toad species can survive up to five days with a body temperature of -6ºC with approximately one-third of their body fluids frozen.  The other tissues are protected because they contain the frost-protective agents glycerin or glucose.  Additionally, in many species the tolerance boundaries are flexible and can change as a result of acclimatization (long-term exposure to particular conditions).  Frog species that remain exposed to the sun despite high diurnal (daytime) temperatures exhibit some fascinating modifications in the skin structure that function as morphological adaptations. Most amphibian skin is fully water permeable and is therefore not a barrier against evaporation or solar radiation. The African savanna frog Hyperolius viridiflavus stores guanine crystals in its skin, which enable it to better reflect solar radiation, thus providing protection against overheating. The tree frog Phyllomedusa sauvagei responds to evaporative losses with gland secretions that provide a greasy film over its entire body that helps prevent desiccation (dehydration). However, behavior is by far the most important factor in thermoregulation. The principal elements in behavioral thermoregulation are basking (heliothermy), heat exchange with substrates such as rock or earth (thigmothermy), and diurnal and annual avoidance behaviors, which include moving to shelter during the day for cooling and hibernating or estivating (reducing activity during cold or hot weather, respectively). Heliothermy is especially common among frogs and toads: it allows them to increase their body temperature by more than 10ºC. The Andean toad Bufo spinulosus exposes itself immediately after sunrise on moist ground and attains its preferred body temperature by this means, long before either ground or air is correspondingly warmed. A positive side effect of this approach is that it accelerates the digestion of the prey consumed overnight, thus also accelerating growth. Thigmothermy is a behavior present in most amphibians, although pressing against the ground serves a dual purpose: heat absorption by conductivity and water absorption through the skin. The effect of thigmothermy is especially evident in the Andean toad during rainfall: its body temperature corresponds to the temperature of the warm earth and not to the much cooler air temperature. Avoidance behavior occurs whenever physiological and morphological adaptations are insufficient to maintain body temperature within the vital range. Nocturnal activity in amphibians with low tolerance for high ambient temperatures is a typical thermoregulatory behavior of avoidance. Seasonal avoidance behavior is extremely important in many amphibians. Species whose habitat lies in the temperate latitudes are confronted by lethal low temperatures in winter, while species dwelling in arid and semi-arid regions are exposed to long dry, hot periods in summer. In amphibians hibernation occurs in mud or deep holes away from frost. North of the Pyrenees Mountains, the natterjack toad offers a good example of hibernation, passing the winter dug deep into sandy ground. Conversely, natterjacks in southern Spain remain active during the mild winters common to the region and are instead forced into inactivity during the dry, hot summer season. Summer estivation also occurs by burrowing into the ground or hiding in cool, deep rock crevasses to avoid desiccation and lethal ambient temperatures. Amphibians are therefore hardly at the mercy of ambient temperatures, since by means of the mechanisms described above they are more than able to exercise some control over their body temperature.