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SAMPLE 2 [生物学类] 题目序号 题型归类 第1题 审题定位题型 第2题 句间关系题型 第3题 审题定位题型 第4题 归纳推导题型 第5题 段落结构题型 The fossil remains of the first flying vertebrates, the pterosaurs, haveintrigued paleontologists for more than two centuries. How such largecreatures, which weighed in some cases as much as a piloted hang-glider and hadwingspans from 8 to 12 meters, solved the problems of powered flight, andexactly what these creatures werereptiles or birdsare among the questionsscientists have puzzled over. Perhaps the least controversial assertion about the pterosaurs is thatthey 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 winglike membrane. The other fingers were short and reptilian, withsharpclaws. In birds the second finger is the principal strut of the wing,which consists primarily of feathers. If the pterosaurs walked on all fours,the three short fingers may have been employed for grasping. When a pterosaurwalked or remained stationary, the fourth finger, and with it the wing, couldonly turn upward in an extended inverted V shape along each side of the animals body. | 
