GWD-9-Q34

rainbowmanutd

Scientistsstudying the physiology of dinosaurs have long debated whether dinosaurs werewarm- or cold-blooded. Thosewho suspect they were warm-blooded point out that dinosaur bone is generally fibro-lamellar in nature; becausefibro-lamellar bone is formed quickly, the bone fibrils, or filaments, are laiddown haphazardly. Consistent with their rapid growth rate, warm-blooded animals, such as birds and mammals, tend toproduce fibro-lamellar bone, whereas reptiles, which are slow-growing andcold-blooded, generally produce bone in which fibrils are laid down parallel to each other. Moreover, like thebone of birds and mammals, dinosaur bone tends to be highly vascularized, orfilled with blood vessels. These characteristics, first recognized in the 1930’s, were documentedin the 1960’s by de Ricqlès, who found highly vascularized, fibro-lamellar bonein several groups of dinosaurs. In the 1970’s, Bakker cited these characteristics as evidence for the warm-bloodednessof dinosaurs. Although de Ricqlès urged caution, arguing for an intermediate type ofdinosaur physiology, a generation of paleontologistshas come to believe that dinosaur bone is mammalianlike. In the 1980’s,however, Bakker’s contention began to be questioned, as a number ofscientists found growth rings in the bonesof various dinosaurs that are much like those in modern reptiles. Bone growthin reptiles is periodic in nature, producing a series of concentric ringsin the bone, not unlike the growth ringsof a tree. Recently, Chinsamy investigated the bones of two dinosaurs from theearly Jurassic period (208-187 million years ago), and found that thesebones also had growth rings; however, theywere also partially fibro-lamellar in nature. Chinsamy’s work raises a questioncentral to the debate over dinosaur physiology: did dinosaurs formfibro-lamellar bone because of an innatelyhigh metabolic rate associated with warm-bloodedness or because of periods ofunusually fast growth that occurred under favorable environmentalconditions? (Although modern reptilesgenerally do not form fibro-lamellar bone, juvenile crocodilesraised underoptimal environmental conditions do.) This question remains unanswered;indeed, taking all the evidence intoaccount, one cannot make a definitive statement about dinosaur physiology onthe basis of dinosaur bone. It may be that dinosaurs had an intermediatepattern of bone structure because theirphysiology was neither typically reptilian, mammalian, nor avian.

GWD-9-Q34 G-9-Q34:

The primary purpose of the passage is to

A.   discuss the influence on otherscientists of Bakker’s argument concerning the warm-bloodedness of dinosaurs

B.    provide evidence that supportsthe claim that dinosaurs were cold-blooded

C.   challenge the contention thatdinosaur bone tissue is innately fibro-lamellar

D.   evaluate the claim thatdinosaur bone tissue provides evidence for the warmbloodedness of dinosaurs

E.   resolve the disagreementbetween de Ricqlès and Bakker over the nature of dinosaur physiology

选D,我在AD间纠结了好久，虽然A没提influence,但是D的evaluate也不对呀，作者只是一直在叙说每个人不同的看法和研究，没有做出评论阿

tubai

up up up ~~

tubai

我的想法跟LZ一样,求NN

tubai

或者是不是作者最后说intermediate pattern,表示他持有中立的态度，也就是evaluate一下这个claim,但是感觉这又最后才涉及了evaluate,还是之前都是作者为了evaluate做到准备。。？