求助阅读大全第4篇，错题1，4，怎么都不能理解原因

The fossil remainsof the first flying vertebrates, the pterosaurs, have intrigued paleontologistsfor more than two centuries. How such large creatures, which weighed in somecases as much as a piloted hang-glider (hang-glider: n. 悬挂式滑翔机) and had wingspans from 8 to 12meters, solved the problems of powered flight, and exactly what these creatureswere—reptiles or birds—are among the questions scientists have puzzled over.

Perhaps the leastcontroversial assertion about the pterosaurs is that they were reptiles. Theirskulls, pelvises, and hind feet are reptilian. [url=]The anatomy of their wings suggests thatthey did not evolve into the class of birds[/url][M1] . 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 extended inverted V-shape along each side ofthe animal’s body.

The pterosaursresembled both birds and bats in their overall structure and proportions. Thisis not surprising 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.

Although scalestypically cover reptiles, the pterosaurs probably had hairy coats. T. H. Huxleyreasoned that flying vertebrates must have been warm-blooded because flyingimplies a high rate of metabolism, which in turn implies a high internaltemperature. Huxley speculated that a coat of hair would insulate against lossof body heat and might streamline the body to reduce drag in flight. The recentdiscovery of a pterosaur specimen covered in long, dense, and relatively thick hairlikefossil material was the first clear evidence that his reasoning was correct.

Efforts to explainhow the pterosaurs 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.

1.       It can be inferred from the passage that scientists nowgenerally agree that the

错题反思；这题怎么都想不通为什么要选Ｄ，不是说whether theyare reptiles or birds , scientists are puzzled over 吗？

(A) enormouswingspan of the pterosaurs enabled them to fly great distances

(B) structureof the skeleton of the pterosaurs suggests a close evolutionary relationship tobats

(C) fossil remains of the pterosaurs reveal how they solvedthe problem of powered flight

(D) pterosaurswere reptiles（D）

(E) pterosaurswalked on all fours

2.     The author views the idea that thepterosaurs became airborne by rising into light winds created by waves as

(A)revolutionary

(B) unlikely

(C)unassailable

(D) probable（B）

(E) outdated

3.     According to the passage, the skeleton of apterosaur can be distinguished from that of a bird by the

(A) size of itswingspan

(B) presence ofhollow spaces in its bones

(C) anatomic origin of its wing strut

(D) presence ofhooklike projections on its hind feet（C）

(E) location ofthe shoulder joint joining the wing to its body

4.     Theideas attributed to T. H. Huxley in the passage suggest that he would mostlikely agree with which of the following statements?

这题也不明白为什么要选Ｂ而不是Ｅ， 选择Ｂ的原因是什么呢？

(A) An animal’sbrain size has little bearing on its ability to master complex behaviors.

(B) An animal’sappearance is often influenced by environmental requirements and physicalcapabilities.

(C) Animalswithin a given family group are unlikely to change their appearancedramatically over a period of time.

(D) The originof flight in vertebrates was an accidental development rather than the outcomeof specialization or adaptation.（B）

(E) Thepterosaurs should be classified as birds, not reptiles.

5.     It can be inferred from the passage thatwhich of the following is characteristic of the pterosaurs?

with it the wing, could only turn upward in anextended inverted V-shape along each side of the animal’s body.

(A) They were unable to fold their wings when not in use.

(B) They hungupside down from branches as bats do before flight.

(C) They flewin order to capture prey.

(D) They werean early stage in the evolution of the birds.（A）

(E) They livedprimarily in a forest-like habitat.

6.     Which of the following best describes theorganization of the last paragraph of the passage?

(A) Newevidence is introduced to support a traditional point of view.

(B) Three explanations for a phenomenon are presented, and eachis disputed by means of specific information.

(C) Threehypotheses are outlined, and evidence supporting each is given.

(D) Recentdiscoveries are described, and their implications for future study areprojected.（B）

(E) A summaryof the material in the preceding paragraphs is presented, and conclusions aredrawn.

7.     It can be inferred from the passage thatsome scientists believe that pterosaurs

or even by rising into light winds from the crests ofwaves

这是原句，故可以推出答案Ａ。

(A) lived near large bodies of water

(B) had sharpteeth for tearing food

(C) wereattacked and eaten by larger reptiles

(D) had longertails than many birds（A）

(E) consumedtwice their weight daily to maintain their body temperature

[M1]That’s the clue for answer question 3.