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标题: GWD-9-36 [打印本页]

作者: linlin2008    时间: 2005-6-3 07:11     标题: GWD-9-36

GWD-9-Q33 to GWD-9-Q36:Scientists studying the physiologyof dinosaurs have long debated whetherdinosaurs were warm- or cold-blooded.Line  Those who suspect they were warm-(5)   blooded point out that dinosaur boneis generally fibro-lamellar in nature;because fibro-lamellar bone is formedquickly, the bone fibrils, or filaments, arelaid down haphazardly. Consistent with(10)  their rapid growth rate, warm-bloodedanimals, such as birds and mammals,tend to produce fibro-lamellar bone,whereas reptiles, which are slowgrowingand cold-blooded, generally(15)  produce bone in which fibrils are laiddown parallel to each other. Moreover,like the bone of birds and mammals,dinosaur bone tends to be highlyvascularized, or filled with blood(20)  vessels. These characteristics,first recognized in the 1930’s,were documented in the 1960’s byde Ricqlès, who found highly vascularized,fibro-lamellar bone in several(25)  groups of dinosaurs. In the 1970’s,Bakker cited these characteristics asevidence for the warm-bloodedness ofdinosaurs. Although de Ricqlès urgedcaution, arguing for an intermediate type(30)  of dinosaur physiology, a generation ofpaleontologists has come to believethat dinosaur bone is mammalianlike.In the 1980’s, however, Bakker’scontention began to be questioned, as a(35)  number of scientists found growth ringsin the bones of various dinosaurs thatare much like those in modern reptiles.Bone growth in reptiles is periodic innature, producing a series of concentric(40)  rings in the bone, not unlike the growthrings of a tree. Recently, Chinsamyinvestigated the bones of two dinosaursfrom the early Jurassic period(208-187 million years ago), and found(45)  that these bones also had growth rings;however, they were also partially fibrolamellarin nature. Chinsamy’s workraises a question central to the debateover dinosaur physiology: did dino-(50)  saurs form fibro-lamellar bone becauseof an innately high metabolic rate associatedwith warm-bloodedness orbecause of periods of unusually fastgrowth that occurred under favorable(55)  environmental conditions? (Althoughmodern reptiles generally do not formfibro-lamellar bone, juvenile crocodilesraised under optimal environmentalconditions do.) This question remains(60)  unanswered; indeed, taking all the evidenceinto account, one cannot makea definitive statement about dinosaurphysiology on the basis of dinosaurbone. It may be that dinosaurs had an(65) intermediate pattern of bone structurebecause their physiology was neithertypically reptilian, mammalian, nor avian.GWD-9-Q36:The author of the passage mentions bone growth patterns in juvenile crocodiles mostlikely in order toA. provide support for the argument that reptiles are not related to dinosaursB. undermine the claim that most reptiles are slow-growingC. offer an explanation as to why juvenile crocodiles differ from most modernreptilesD. suggest the juvenile crocodiles have a type of physiology intermediate betweenthat of mammals and that of reptilesE. suggest that the presence of fibro-lamellar bone does not resolve the debate over请教,我实在不知道怎样推出E答案(正确答案给的是E),我没思路,或许是没看懂谢谢
作者: girls    时间: 2005-6-3 07:16

Scientists studying the physiology of dinosaurs have long debated whether dinosaurs were warm- or cold-blooded. 研究恐龙生理结构的科学家们长期以来对于恐龙到底是冷血动物还是温血动物这个问题争论不休。

Line Those who suspect they were warm- (5) blooded point out that dinosaur bone is generally fibro-lamellar in nature; because fibro-lamellar bone is formed quickly, the bone fibrils, or filaments, are laid down haphazardly. 认为恐龙是温血动物的科学家指出,恐龙的骨头通常是成fibro薄片状的。因为fibro薄片状的骨头生长的很快,这些骨头纤维或者细丝都是随意生长的。

Consistent with (10) their rapid growth rate, warm-blooded animals, such as birds and mammals, tend to produce fibro-lamellar bone, whereas reptiles, which are slowgrowing and cold-blooded, generally (15) produce bone in which fibrils are laid down parallel to each other. 为了和快速生长的速度相一致,这些温血动物如鸟类和哺乳动物,往往长出fibro纤维状的骨头,但是生长较慢的冷血爬行动物,通常长出的骨头的纤维是彼此平行的。

Moreover, like the bone of birds and mammals, dinosaur bone tends to be highly vascularized, or filled with blood (20) vessels. 而且,与鸟和哺乳动物的骨头一样,恐龙的骨头往往是高度脉管化的,或者充满了血管。

These characteristics, first recognized in the 1930’s, were documented in the 1960’s by de Ricqlès, who found highly vascularized, fibro-lamellar bone in several (25) groups of dinosaurs. In the 1970’s, Bakker cited these characteristics as evidence for the warm-bloodedness of dinosaurs.这些在30年代首次确认的特征,由DR在60年代记录在案,DR在几个不同种群的恐龙中发现了高度脉管化,fibro纤维化的骨头。 70年代,B引用这些特征作为恐龙的温血动物的证据。

Although de Ricqlès urged caution, arguing for an intermediate type (30) of dinosaur physiology, a generation of paleontologists has come to believe that dinosaur bone is mammalianlike. 尽管DR提出了警告,认为从恐龙生理学的角度而言可能存在着中间类型,但是很多古生物学家开始相信恐龙的骨头是哺乳类的。

In the 1980’s, however, Bakker’s contention began to be questioned, as a (35) number of scientists found growth rings in the bones of various dinosaurs that are much like those in modern reptiles.但是到了80年代,B的学说开始被人们质疑,因为很多科学家发现不同种类的恐龙的骨头生长环和现代爬行动物的很相像。

Bone growth in reptiles is periodic in nature, producing a series of concentric (40) rings in the bone, not unlike the growth rings of a tree. 爬行动物的骨头生长是周期性的,产生了一系列的同心环,和树的年轮的增长是一样的。

Recently, Chinsamy investigated the bones of two dinosaurs from the early Jurassic period (208-187 million years ago), and found (45) that these bones also had growth rings; however, they were also partially fibrolamellar in nature. 最近,C调查了J时代早期的2只恐龙的骨头,发现这些骨头也有生长环;但是这些生长环也部分是fibro纤维状的。Chinsamy’s work raises a question central to the debate over dinosaur physiology: did dino- (50) saurs form fibro-lamellar bone because of an innately high metabolic rate associated with warm-bloodedness or because of periods of unusually fast growth that occurred under favorable (55) environmental conditions? (Although modern reptiles generally do not form fibro-lamellar bone, juvenile crocodiles raised under optimal environmental conditions do.) C的工作对恐龙生理学提出了一个关键性的问题:恐龙生长fibro纤维状的骨头是否是因为在适宜的环境中的反常快速生长阶段引起的?(尽管现在的爬行动物普遍上都没有fibro纤维状的骨头,但是幼年的鳄鱼在最佳的环境下会生长这样的骨头)

This question remains (60) unanswered; indeed, taking all the evidence into account, one cannot make a definitive statement about dinosaur physiology on the basis of dinosaur bone. It may be that dinosaurs had an (65) intermediate pattern of bone structure because their physiology was neither typically reptilian, mammalian, nor avian. 这个问题仍然没有得到解决,事实上,考虑到所有的证据,人们不能基于恐龙的骨头得到一个关于恐龙生理学的定论。有可能恐龙在骨的构造上存在着中间阶段,因为他们的骨头既不是典型的爬行类,哺乳类或者鸟类。

由此可见,对于恐龙骨头的不同的证据,使得人们认为他一会儿是这样(有纤维化的骨头),一会儿是那样的(和爬行动物一样,有周期性的同心环)。C发现恐龙的骨头有同爬行动物一样的同心环,但却是部分纤维化的。而尽管C的工作提出了关键性的问题,但是仍然得不到解答。紧接着举了幼年鳄鱼的例子,因此此例子是为了支持这一点,即C的发现不能解决问题。E正好说明这一点。而ABCD显然不相关。


作者: diatomss    时间: 2005-6-4 07:14

强,顶!!!


作者: linlin2008    时间: 2005-6-6 07:25

thanks   a    lot  !!




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