Direction:- Read the given passage and answer the question that follow  by selecting the most appropriate option. 1.The fossil remains of the first flying vertebrates, the pterosaurs, have intrigued paleontogists for more than two centuries. How such large creaturs, solved the problems of powered flight, and exactly what these creatures were-reptlies or birds are among the questions scientists have puzzled over. 2. Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. Their skills, pelvises and hind feet are reqtilian. The anatiomy of their wings suggests that they did not evolove into the class of birds. In pterosaurs, greatly elongated fourth finger of each forelimb supported a wing like membrane. inbirds the second finger is the principled stationary, the fourth finger and with it the wing, could only turn upward in an extended inverted V-shape alongsie of the animal's body. Both the ptrosaurs and the birds have hollow bones, a feature that represents a saving in weight. in the birds, however, these bones are reinfoced more massively by internal struts. 3. Although scales typically cover reptiles, the pterosaurs probavbly had hairy coast. the pterosaurs probably had hairy coats, the recent discovery of a pterosaur specimen covered in long, dense and relatiely thick hair-like fossil material, wat the first clear evidence that this reasoning was correct. Efforts to explain how the pterosaurs became air borne have led to suggestion that they launced themselves by jumping from cliffts, by droping from trees, or even by rising into light winds from the crests of waves. Which is the characteristic of ptersaur ?