原文如下
Thefossil remains of the first flying vertebrates, the pterosaurs, have intriguedpaleontologists for more than two centuries. How such large creatures, whichweighed in some cases as much as a piloted hang-glider (hang-glider: n. 悬挂式滑翔机) and had wingspans from 8 to 12 meters, solved theproblems of powered flight, and exactly what these creatures were—reptiles orbirds—are among the questions scientists have puzzled over. Perhaps the least controversialassertion about the pterosaurs is that they were reptiles. Their skulls,pelvises, and hind feet are reptilian. Theanatomy of their wings suggests that they did not evolve into the class ofbirds. In pterosaurs a greatly elongated fourth finger of each forelimbsupported a wing-like membrane. The other fingers were short and reptilian,with sharp claws. In birds the second finger is the principal strut of thewing, which consists primarily of feathers. If the pterosaurs walked on allfours, the three short fingers may have been employed for grasping. When apterosaur walked or remained stationary, the fourth finger, and with it thewing, could only turn upward in an extendedinverted V-shape along each side of the animal’s body. Thepterosaurs resembled bothbirds and bats in their overall structure and proportions. This is notsurprising because the design of any flying vertebrate is subject toaerodynamic constraints. Both the pterosaurs and the birds have hollow bones, afeature that represents a savings in weight. In the birds, however, these bonesare reinforced more massively by internal struts. Althoughscales typically cover reptiles, the pterosaurs probably had hairy coats. T. H.Huxley reasoned that flying vertebrates musthave been warm-blooded because flying implies a high rate of metabolism,which in turn implies a high internal temperature. Huxley speculated that acoat of hair would insulate against loss of body heat and might streamline the body to reduce drag in flight. The recent discovery of a pterosaurspecimen covered in long, dense, and relatively thick hairlike fossil materialwas the first clear evidence that his reasoning was correct. Effortsto explain how thepterosaurs became airborne have led to suggestions that they launchedthemselves by jumping from cliffs, by dropping from trees, or even by risinginto light winds from the crests of waves. Each hypothesis has itsdifficulties. The first wrongly assumes that the pterosaurs’ hind feetresembled a bat’s and could serve as hooks by which the animal could hang inpreparation for flight. The second hypothesis seems unlikely because largepterosaurs could not have landed in trees without damaging their wings. Thethird calls for high waves to channel updrafts. The wind that made such waveshowever, might have been too strong for the pterosaurs to control their flightonce airborne. 7. It can be inferred from the passage that somescientists believe that pterosaurs [size=10.000000pt](A) lived near large bodies of water
(B) had sharp teeth for tearing food
(C) were attacked and eaten by larger reptiles(D) had longer tails than many birds
[size=10.000000pt](E) consumed twice their weight daily to maintaintheir body temperature
[size=10.000000pt](D) had longer tails than many birds
[size=10.000000pt] 想求助一下这道题 答案选A，在文章里有什么地方可以证明吗
[size=10.000000pt]我有想到可能是红色字体的那个streamline，但是我觉得这个指的是把...变成流线型，不一定代表就是用水
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发表于 2019-9-11 20:35:21
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