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《考研英语阅读理解100篇 高分版》 Unit 25 - TEXT TWO

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2019年02月26日

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When Archaeopteryx, a feathered skeleton that was seemingly half dinosaur and half bird, turned up in 1862—three years after the publication of The Origin of Species—the origin of birds became a subject of raging debate among palaeontologists. Suggestions that they were the direct descendants of theropod dinosaurs (a group of bipedal meat-eaters that include Allosaurus, Velociraptor and Tyrannosaurus) caused quite a flap. Today, most researchers agree that birds are, indeed, a branch of the Dinosauria. How they made the transition from the land to the sky, though, has yet to be agreed. But a paper in this week's Current Biology, by Christopher Glen and Michael Bennett of the University of Queensland, makes a strong case that they did it by jumping.
Considering the diversity of life on Earth, flight is surprisingly rare. It has evolved only four times: among the insects about 300m years ago, the pterosaurs (230m), the birds (150m) and the bats (50m). That suggests it is a hard trick to pull off. For birds, there is general agreement that feathers came before flight. Fossils from north-eastern China show animals that had feathers but clearly could not have flown, as well as ones that look like proper birds. The best guesses are that feathers evolved either for insulation (as fur did in mammals) or for display, and that natural selection took advantage by turning them into a means of transport.
There are two broad schools of thought about what happened next. One argues that birds' immediate ancestors lived in trees. Members of this school think that powered flight developed as a natural extension of gliding (such controlled falling is used as a way of travelling from tree to tree by several arboreal species today). Gliding itself developed because of the lift provided by feathered forearms.
The alternative is that flight evolved on the ground. Some researchers who belong to this school of thought suggest that the power provided by flapping protowings may have given their owners an edge in the pursuit of prey. Others hypothesise that feathery forearms helped animals steer and stabilise themselves.
Unfortunately, behaviour does not fossilise, so it looked as though the question might never be answered. But Dr. Glen, a palaeobiologist, and Dr. Bennett, a biomechanic, think they have worked out how to do so. Their crucial observation is that in modern birds the curvature of the third toe (which carries a lot of weight during walking and climbing) varies with species' lifestyles. Birds that spend lots of time climbing around on the trunks of trees have dramatically curved third toes. Those that hop around on branches have mildly curved ones. Those that forage mainly on the ground have the least curved of all.
The two researchers compared these observations with their findings for the bird-like dinosaurs and dinosaur-like birds of China. They noticed that the toes of both feathered dinosaurs and of the earliest flying birds were similar to those of modern birds that spend most of their time on the ground. Flight, in other words, came before birds took to the trees. They are not fallen angels, but risen reptiles.
1. Which one of the following statements is NOT true of the current debate on the origin of birds?
[A] The opinion that birds were the direct descendants of dinosaurs gives the world a shock.
[B] Palaeontologists have get consensus on the species' transition from the land to the sky.
[C] Palaeontologists have different opinions on the process of the transition.
[D] The paper in this week's Current Biology demonstrates that the species moved by hopping before they flied.
2. The reason why flight is surprisingly rare is that _____.
[A] life on Earth is diversified
[B] many species of this kind were eliminated during evolution
[C] feathers evolved not for a means of transport
[D] it is very hard to have such evolution
3. The two schools of thought have different opinions on _____.
[A] the functions of feathered forearms in transition from ground to sky
[B] the location of living place before the animals' evolution to birds
[C] the development of powered flight
[D] the power provided by either gliding or flapping
4. The conclusion of the study carried out by Dr. Glen and Dr. Bennet is that _____.
[A] powered flight developed as feathered forearms provided lift
[B] flight evolved on the ground before they descend on the trees
[C] earliest birds share similar toes with their modern counterparts
[D] earliest flying birds evolved from feathered dinosaurs
5. Which one of the following statements is NOT true of opinions of Dr. Glen and Dr. Bennet?
[A] Birds realized the transition from reptile to flight by jumping.
[B] Dinosaurs are, as a matter of fact, the direct descendents of birds.
[C] Feathers evolves not for the purpose of flight.
[D] The bird's behaviours is indeed fossilized by their various shape of the third toe.

1. Which one of the following statements is NOT true of the current debate on the origin of birds?
[A] The opinion that birds were the direct descendants of dinosaurs gives the world a shock.
[B] Palaeontologists have get consensus on the species' transition from the land to the sky.
[C] Palaeontologists have different opinions on the process of the transition.
[D] The paper in this week's Current Biology demonstrates that the species moved by hopping before they flied.
1. 关于鸟类起源的争论,下列哪个陈述是错误的?
[A] 鸟类是恐龙的直接后裔,这个观点让世界震惊。
[B] 古生物学家就该物种从地上到空中的转化这个问题达成了一致。
[C] 古生物学家对于转变的过程有不同的观点。
[D] 本周的《当今生物》上的论文表明,它们在掌握飞行能力之前是靠跳跃来移动的。
答案:D 难度系数:☆☆
分析:细节题。选项A,第一段提到了这点。选项B,第一段提到,许多研究者同意鸟类是恐龙的一个分支,与这点相符。选项C,第一段提到了他们在该问题上有争议。选项D,鸟类是靠跳跃实现由地到空的转变,而不是移动。因此,答案为D。
2. The reason why flight is surprisingly rare is that _____.
[A] life on Earth is diversified
[B] many species of this kind were eliminated during evolution
[C] feathers evolved not for a means of transport
[D] it is very hard to have such evolution
2. 飞行的动物很少,是因为 _____。
[A] 地球上的生物是多元化的
[B] 飞行动物的许多物种在进化过程中都灭绝了
[C] 羽毛并不是为了移动的方式才进化出来的
[D] 发生这样的进化很难
答案:D 难度系数:☆☆☆☆
分析:细节题。根据第二段:Considering the diversity of life on Earth, flight is surprisingly rare. It has evolved only four times: among the insects about 300m years ago, the pterosaurs (230m), the birds (150m) and the bats (50m). That suggests it is a hard trick to pull off. 即飞行动物只进化了四次,进化是很艰难的过程,因此飞行动物的品种少。所以,答案为D。
3. The two schools of thought have different opinions on _____.
[A] the functions of feathered forearms in transition from ground to sky
[B] the location of living place before the animals' evolution to birds
[C] the development of powered flight
[D] the power provided by either gliding or flapping
3. 两派在 _____ 上有不同的观点。
[A] 长有羽毛的前臂在从地上到空中转变中的作用
[B] 这些动物进化为鸟类之前生活的地方
[C] 动力飞行的发展
[D] 力量是由滑翔或者拍动翅膀提供的
答案:C 难度系数:☆☆☆
分析:细节题。根据第三段和第四段,两派科学家在鸟类的飞行是靠滑行还是靠拍动翅膀提供的升力而形成的这一点上有分歧,因此,选项C符合题意。选项B比较具有干扰性,文章中提到,两种观点认为,这些动物在进化为鸟类之前是分别住在地面上和树上的,但这只是一个表面的原因,深层次的原因还在于选项C。
4. The conclusion of the study carried out by Dr. Glen and Dr. Bennet is that _____.
[A] powered flight developed as feathered forearms provided lift
[B] flight evolved on the ground before they descend on the trees
[C] earliest birds shared similar toes with their modern counterparts
[D] earliest flying birds evolved from feathered dinosaurs
4. Glen博士和Bennet博士在该研究中得到的结论是 _____。
[A] 长有羽毛的前臂提供了升力,从而使得动力飞行发展起来
[B] 飞行是在地上发展而来的,发生在它们落到树上之前
[C] 最早飞行的鸟类与现代鸟类的第三个脚趾相似
[D] 最早的会飞的鸟是从长羽毛的恐龙进化来的
答案:B 难度系数:☆☆☆
分析:细节题。根据第五段和第六段,他们通过研究鸟类的脚趾得出结论,鸟类一开始是在地上生活,在转移到树上生活之前就可以飞翔了,那么它们的飞翔是从地面上发展而来的。因此,答案为B。选项C具有一定的迷惑性,但是要注意的是modern counterparts的范围过于广泛,而文中说的是modern birds that spend most of their time on the ground,因此该选项错误。
5. Which one of the following statements is NOT true of opinions of Dr. Glen and Dr. Bennet?
[A] Birds realized the transition from reptile to flight by jumping.
[B] Dinosaurs are, as a matter of fact, the direct descendents of birds.
[C] Feathers evolves not for the purpose of flight.
[D] The bird's behaviour is indeed fossilized by their various shape of the third toe.
5. 关于Glen博士和Bennet博士的观点,下列哪个陈述是错误的?
[A] 鸟类依靠跳跃实现了从爬行动物到飞行动物的转变。
[B] 恐龙实际上是鸟类的直接后裔。
[C] 鸟类的羽毛不是为了飞行而进化形成的。
[D] 鸟类的行为实际上是由其第三个脚趾的不同形状决定的。
答案:B 难度系数:☆☆☆
分析:细节题。选项B,这一点不符合他们的观点,文章中的意思应该是鸟类是恐龙的直接后裔。选项A是正确的,这一点在第一段中就有所提及:But a paper in this week's Current Biology, by Christopher Glen and Michael Bennett of the University of Queensland, makes a strong case that they did it by jumping. 选项C的表述也是正确的,因为文章提到,羽毛的出现甚至是在鸟类掌握了飞行能力之后,因此不是为了这个目的。选项D的表述是正确的,文章倒数第二段提到Unfortunately, behaviour does not fossilise, so it looked as though the question might never be answered. But Dr. Glen, a palaeobiologist, and Dr. Bennett, a biomechanic, think they have worked out how to do so. 进而指出他们采用的方法就是研究鸟类的第三脚趾。因此,答案为B。

当始祖鸟这种看上去一半是恐龙一半是鸟类的有羽毛的动物的骨架于1862年被发现,也就是《物种起源》出版的三年后,鸟类的起源成为古生物学家激烈争论的主题。有人提出,它们是兽脚亚目的恐龙(一类两足食肉恐龙,包括异龙、速龙和霸王龙)的直接后裔,这引起了一片哗然。现在,大多数研究者同意,鸟类实际上是恐龙的一个分支。但是,它们是如何从陆地转到空中生活的,在这个问题上还存在分歧。但是本周的《当今生物》上发表了昆士兰大学的Christopher Glen和Michael Bennett的一篇文章,有力地证明了鸟类正是靠跳跃实现了这种转变的。
鉴于陆地上生命的多样性,飞行动物的种类相对是极少的。飞行动物只进化过四次:3亿年前昆虫的进化,2.3亿年前的翼龙,1.5亿年前的鸟类和5千万年前的蝙蝠。这表明了进化是艰难的历程。大家普遍同意,在能够飞行之前,鸟类已先长出了羽毛。在中国东北发现的化石表明,当时拥有羽毛的动物并不能飞行,即使那些看起来完全像鸟类的也是这样。可能的情况就是,羽毛的出现或者是充当隔离层(作用和哺乳动物的皮毛一样),或者是为了好看,而自然选择又将它们转变成运动的工具。
对于接下来的进化,有两派不同看法。一派认为,鸟类的直系祖先生长在树上,该派成员认为,滑行(今天还有一些树栖动物依靠这种有控制的坠落从一棵树转移到另外一棵树上)自然会发展成为飞行。滑行自身也会发展,因为长了羽毛的前臂为其提供了升力。
另外一派的观点是,飞行是从地面活动发展而来的。该派的一些研究者认为,相当于翅膀的那个部分拍动起来产生的动力给了这些动物捕食的能力。其他的一些假设还有,长了羽毛的前臂有助于动物转向或保持平衡。
不幸的是,动作不能变成化石,因此这个问题看起来可能永远都没有答案了。但是古生物学家Glen博士和生物力学家Bennett博士认为,他们已经找出了具体的方案。他们的核心观察是现代鸟类第三个脚趾(在行走或爬行的时候,这个脚趾承载许多重量)的弯曲度因鸟类生活方式的不同而有差异。多数时间在树干上爬行的鸟类的第三个脚趾非常弯曲,而在树枝上跳来跳去的鸟类的第三个脚趾稍微弯曲,而那些主要在地上搜索食物的鸟类的第三个脚趾是最不弯曲的。
这两位研究者将这些观察结果与对中国的类鸟恐龙和类恐龙鸟的发现做了比较,他们发现,有羽毛的恐龙和最早的会飞行的鸟类的脚趾与那些大多数时间在地上活动的现代鸟类相似。换句话说,鸟类在上树生活之前就可以飞翔了。它们不是坠落的天使,而是飞起来的爬行动物。
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