『新东方在线托福阅读』为托福考生准备了ETS托福TPO/Official 48 Passage 2阅读练习：According to paragraph 2, which of the following is true of the teeth of carnivores?真题题目及答案解析，TPO/Official 48 Passage 2阅读原文范文音频翻译

托福TPO/Official 48 Passage 2阅读原文According to paragraph 2, which of the following is true of the teeth of carnivores?题目答案及解析-新东方托福官方网校手机版

确定灭绝的恐龙吃哪种食物很困难，但是我们可以推断出它们在某些方面的饮食偏好。

Determining what extinct dinosaurs ate is difficult, but we can infer some aspects of their dietary preferences.

传统上，此信息来自直接证据（例如胃内容）和间接证据（例如在特定身体特征与现存动物饮食之间建立关联，然后推断恐龙的习性）。

Traditionally, this information has been derived from direct evidence, such as stomach contents, and indirect evidence, such as establishing a correlation between particular body characteristics and diets of living animals and then inferring habits for dinosaurs.

像家猫和狗这样的动物在嘴的前部有巨大的犬齿，而在它们的下颌后部有更小的同样锋利的牙齿。

Animals such as house cats and dogs have large, stabbing canine teeth at the front of the mouth and smaller, equally sharp teeth farther back in their jaws.

这些动物中许多还带有锋利的爪子。

Many of these animals are also armed with sharp claws.

牙齿和爪子作为掠食性工具的优势显而易见。

The advantage of teeth and claws as predatory tools is obvious.

现在考虑牛，马，兔子和老鼠等动物。

Now consider animals like cows, horses, rabbits, and mice.

这些动物的下颌后部有扁平的牙齿，它们与磨刀石相似，具有和磨刀石相同的功能。

These animals have flat teeth at the back of the jaw that are analogous to and have the same function as grindstones.

与食肉动物切肉和刺肉的牙齿不同，这些动物的牙齿在消化前会研磨并切碎植物材料。

Unlike the meat-slicing and stabbing teeth of carnivores, the teeth of these animals grind and shred plant material before digestion.

在头骨的其他部位存在更多线索。

More clues exist in other parts of the skull.

狗和猫等食肉动物的下颌关节与齿排在同一高度上，它具有机械优势，从而使颚以惊人的速度闭合，并迫使上齿以较高的精度咬合下齿。

The jaw joint of carnivores such as dogs and cats has the mechanical advantage of being at the same level as the tooth row, allowing the jaws to close with tremendous speed and forcing the upper teeth to occlude against the lower teeth with great precision.

在食草动物中，快速下颌闭合不太重要。

In herbivorous animals, rapid jaw closure is less important.

由于草食动物的扁平牙齿就像磨刀石一样工作，因此颌骨必须左右移动和前后移动。

Because the flat teeth of herbivores work like grindstones, however, the jaws must move both side to side and front to back.

许多高级草食动物（如牛）的下颌关节与齿排的位置不同，从而可以横向撕裂，切碎和压缩植物材料。

The jaw joints of many advanced herbivores, such as cows, lie at a different level than the tooth row, allowing transverse tearing, shredding, and compression of plant material.

如果我们将这样的观察扩展到灭绝的恐龙，即使我们不能确定恐龙确切的饮食，我们可以推断出它们的饮食偏好（例如肉食和草食）。

If we extend such observations to extinct dinosaurs, we can infer dietary preferences (such as carnivory and herbivory), even though we cannot determine the exact diet.

鸭嘴恐龙被称为鸭嘴龙，这是一个很好的例子，其下颌关节低于牙齿排的水平，这可能有助于它们磨碎坚韧的纤维状植物。

The duck-billed dinosaurs known as hadrosaurs are a good example of a group whose jaw joint is below the level of the tooth row, which probably helped them grind up tough, fibrous vegetation.

古生物学家希望对恐龙的饮食有更加具体的了解，而不仅仅是将食肉动物与食草动物区分开。

Paleontologists would like to be much more specific about a dinosaur’s diet than simply differentiating carnivore from herbivore.

这种更高层次的分析需要恐龙食物的直接化石证据。

This finer level of resolution requires direct fossil evidence of dinosaur meals.

胃内容物很少被保存，但是当它们存在时，我们就可以确定这些动物正在吃什么。

Stomach contents are only rarely preserved, but when present, allow us to determine exactly what these animals were eating.

在腔骨龙标本（一种小的，长颈的恐龙）的胃中含有来自相同物种的幼年动物的骨头。

In the stomach contents of specimens of Coelophysis (a small, long-necked dinosaur) are bones from juvenile animals of the same species.

曾有一段时间，它们被认为代表了胚胎动物，这表明这种小恐龙产下的是活的幼崽，而不是产卵。

At one time, these were thought to represent embryonic animals, suggesting that this small dinosaur gave birth to live young rather than laying eggs.

进一步的研究表明，这些小恐龙太大了，而且发育得太快，以至于没有孵化的幼龄。

Further research indicated that the small dinosaurs were too large and too well developed to be prehatchling young.

另外，体腔内的幼体大小不同。

In addition, the juveniles inside the body cavity were of different sizes.

所有证据表明，这些都是猎物的遗骸，而成年后的腔骨龙至少部分是食同类的。

All the evidence points to the conclusion that these are the remains of prey items and that, as an adult, Coelophysis was at least in part a cannibal.

胃内容物化石并不局限于食肉恐龙。

Fossilized stomach contents are not restricted to carnivorous dinosaurs.

在少数罕见的案例中，其中的大部分是“木乃伊”（保存异常完好的标本），人们在鸭嘴龙的体腔内发现了植物化石。

In a few rare cases, most of them “mummies” (unusually well preserved specimens), fossilized plant remains have been found inside the body cavity of hadrosaurs.

一些古生物学家认为，这些代表的是不断蓄积（的食物），而不是最终的食物。

Some paleontologists have argued that these represent stream accumulations rather than final meals.

这些案件中最著名的是斯特恩伯格夫妇收集的第二具埃德蒙龙木乃伊。

The best known of these cases is the second Edmontosaurus mummy collected by the Sternbergs.

该标本的胸腔位于德国的森肯贝格博物馆中，里面是针叶树针，树枝，种子和水果的化石残骸。

In the chest cavity of this specimen, which is housed in the Senckenberg Museum in Germany, are the fossil remains of conifer needles, twigs, seeds, and fruits.

在加拿大艾伯塔省的冠龙标本中也有类似的发现，表明至少有两种白垩纪晚期的鸭嘴龙以当今北方林地中常见的树木为食。

Similar finds in Corythosaurus specimens from Alberta, Canada, have also been reported, indicating that at least two kinds of Late Cretaceous hadrosaurs fed on the sorts of trees that are common in today’s boreal woodlands.

直接证据的第二种形式来自粪化石（石化的身体废物）。

A second form of direct evidence comes from coprolites (fossilized bodily waste).

有几个恐龙化石所在地保存着粪化石。

Several dinosaur fossil localities preserve coprolites.

粪便化石为恐龙的饮食习惯提供了明确的证据。

Coprolites yield unequivocal evidence about the dietary habits of dinosaurs.

动植物的许多部位对动物的消化系统具有极强的抵抗力，几乎没有任何改变就可以完全排出体外。

Many parts of plants and animals are extremely resistant to the digestive systems of animals and pass completely through the body with little or no alteration.

对粪化石的研究表明，一些食草恐龙的饮食相对多样化，而其他恐龙似乎是专家，以特定类型的植物为食。

Study of coprolites has indicated that the diets of some herbivorous dinosaurs were relatively diverse, while other dinosaurs appear to have been specialists, feeding on particular types of plants.

从粪化石推断饮食的问题在于很难准确地将特定的粪化石与特定的恐龙联系起来。

The problem with inferring diets from coprolites is the difficulty in accurately associating a particular coprolite with a specific dinosaur.

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

According to paragraph 2, which of the following is true of the teeth of carnivores?

In paragraph 2, the author compares the teeth of cows, horses, rabbits, and mice to grindstones in order to explain

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.

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

According to paragraphs 3 and 4, what can studies of living animals help scientists determine about individual dinosaurs?

According to paragraph 5, all of the following support the claim that the adult Coelophysis sometimes ate young Coelophysis EXCEPT:

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

What explanation is given in paragraph 7 to support the idea that coprolites are a good source of information about what dinosaurs ate?

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

According to paragraph 7, what has the study of coprolites revealed about dinosaur eating habits?

Which of the following questions is NOT answered in the passage?

Look at the four squares  that indicate where the following sentence could be added to the passage. Unfortunately, studies of living animals provide only a very general understanding of what various dinosaurs ate.  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.

Determining Dinosaur Diet Determining what extinct dinosaurs ate is difficult, but we can infer some aspects of their dietary preferences. Traditionally, this information has been derived from direct evidence, such as stomach contents, and indirect evidence, such as establishing a correlation between particular body characteristics and diets of living animals and then inferring habits for dinosaurs. Animals such as house cats and dogs have large, stabbing canine teeth at the front of the mouth and smaller, equally sharp teeth farther back in their jaws. Many of these animals are also armed with sharp claws. The advantage of teeth and claws as predatory tools is obvious. Now consider animals like cows, horses, rabbits, and mice. These animals have flat teeth at the back of the jaw that are analogous to and have the same function as grindstones. Unlike the meat-slicing and stabbing teeth of carnivores, the teeth of these animals grind and shred plant material before digestion. More clues exist in other parts of the skull. The jaw joint of carnivores such as dogs and cats has the mechanical advantage of being at the same level as the tooth row, allowing the jaws to close with tremendous speed and forcing the upper teeth to occlude against the lower teeth with great precision. In herbivorous animals, rapid jaw closure is less important. Because the flat teeth of herbivores work like grindstones, however, the jaws must move both side to side and front to back. The jaw joints of many advanced herbivores, such as cows, lie at a different level than the tooth row, allowing transverse tearing, shredding, and compression of plant material.  If we extend such observations to extinct dinosaurs, we can infer dietary preferences (such as carnivory and herbivory), even though we cannot determine the exact diet.  The duck-billed dinosaurs known as hadrosaurs are a good example of a group whose jaw joint is below the level of the tooth row, which probably helped them grind up tough, fibrous vegetation. Paleontologists would like to be much more specific about a dinosaur’s diet than simply differentiating carnivore from herbivore.  This finer level of resolution requires direct fossil evidence of dinosaur meals. Stomach contents are only rarely preserved, but when present, allow us to determine exactly what these animals were eating. In the stomach contents of specimens of Coelophysis (a small, long-necked dinosaur) are bones from juvenile animals of the same species. At one time, these were thought to represent embryonic animals, suggesting that this small dinosaur gave birth to live young rather than laying eggs. Further research indicated that the small dinosaurs were too large and too well developed to be prehatchling young. In addition, the juveniles inside the body cavity were of different sizes. All the evidence points to the conclusion that these are the remains of prey items and that, as an adult, Coelophysis was at least in part a cannibal. Fossilized stomach contents are not restricted to carnivorous dinosaurs. In a few rare cases, most of them “mummies” (unusually well preserved specimens), fossilized plant remains have been found inside the body cavity of hadrosaurs. Some paleontologists have argued that these represent stream accumulations rather than final meals. The best known of these cases is the second Edmontosaurus mummy collected by the Sternbergs. In the chest cavity of this specimen, which is housed in the Senckenberg Museum in Germany, are the fossil remains of conifer needles, twigs, seeds, and fruits. Similar finds in Corythosaurus specimens from Alberta, Canada, have also been reported, indicating that at least two kinds of Late Cretaceous hadrosaurs fed on the sorts of trees that are common in today’s boreal woodlands. A second form of direct evidence comes from coprolites (fossilized bodily waste). Several dinosaur fossil localities preserve coprolites. Coprolites yield unequivocal evidence about the dietary habits of dinosaurs. Many parts of plants and animals are extremely resistant to the digestive systems of animals and pass completely through the body with little or no alteration. Study of coprolites has indicated that the diets of some herbivorous dinosaurs were relatively diverse, while other dinosaurs appear to have been specialists, feeding on particular types of plants. The problem with inferring diets from coprolites is the difficulty in accurately associating a particular coprolite with a specific dinosaur.