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标题: 小安阅读第四篇第七题求解 [打印本页]
作者: hey77got 时间: 2019-9-11 20:35
标题: 小安阅读第四篇第七题求解
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
作者: Hellen啊 时间: 2019-9-20 20:09
我也在做这一篇，但我的问题是第5小题。不能折叠翅膀是哪句话看出来的啊，是这句吗?When a pterosaurwalked or remained stationary, the fourth finger, and with it the wing, could onlyturn upward in an extended inverted V-shape along each side of the animal’sbody. 我也想象不出来这个动物是怎么样的
作者: Hellen啊 时间: 2019-9-20 20:13
你这个第7题的A选项，是从最后一题看出来的。原文的第三个假设
even by risinginto light winds from the crests of waves
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.
是海浪导致的风（这个肯定是事实）
可能使得它飞起来（假设，文中也说了不大可能，因为海浪的风可能太大了导致它不能控制）
作者: 利他. 时间: 2019-9-28 10:06
对只能算bend不能算fold
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