2015年MBA阅读理解强化练习题2
The fossil remains of the first flying vertebrates, the pterosaurs, haveintrigued paleontologists for more than two centuries. How such large creatures,
which weighed in some cases as much as a piloted hang-glider and had wingspans
from 8 to 12 meters, solved the problems of powered flight, and exactly what
these creatures were — reptiles or birds — are among the questions scientists
have puzzled over.
Perhaps the least controversial assertion about the pterosaurs is that they
were reptiles. Their skulls, pelvises, and hind feet are reptilian. The anatomy
of their wings suggests that they did not evolve into the class of birds. In
pterosaurs a greatly elongated fourth finger of each forelimb supported a
winglike membrane. The other fingers were short and reptilian, with sharpclaws.
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 pterosaur walked or remained
stationary, the fourth finger, and with it the wing, could only turn upward in
an extended inverted V shape along each side of the animal’s body.
The pterosaurs resembled both birds and bats in their overall structure and
proportions. This is not surprising because the design of any flying vertebrate
is subject to aerodynamic constraints. Both the pterosaurs and the birds have
hollow bones, a feature that represents a savings in weight. In the birds,
however, these bones are reinforced more massively by internal struts.
Although scales typically cover reptiles, the pterosaurs probably had hairy
coats. T. H. Huxley reasoned that flying vertebrates must have been warm-blooded
because flying implies a high rate of metabolism, which in turn implies a high
internal temperature. Huxley speculated that a coat of hair would insulate
against loss of body heat and might streamline the body to reduce drag in
flight. The recent discovery of a pterosaur specimen covered in long, dense, and
relatively thick hairlike fossil material was the first clear evidence that his
reasoning was correct.
Efforts to explain how the pterosaurs became airborne have led to
suggestions that they launched themselves by jumping from cliffs, by dropping
from trees, or even by rising into light winds from the crests of waves. Each
hypothesis has its difficulties. The first wrongly assumes that the pterosaurs’
hind feet resembled a bat’s and could serve as hooks by which the animal could
hang in preparation for flight. The second hypothesis seems unlikely because
large pterosaurs could not have landed in trees without damaging their wings.
The third calls for high waves to channel updrafts. The wind that made such
waves however, might have been too strong for the pterosaurs to control their
flight once airborne.
1. It can be inferred from the text that scientist now generally agree that
the
enormous wingspan of the pterosaurs enabled them to fly great
distances.
structure of the skeleton of the pterosaurs suggests a close
evolutionary relationship to bats.
fossil remains of the pterosaurs reveal how they solved the problem of
powered flight.
pterosaurs were reptiles.
2. The author views the idea that the pterosaurs became airborne by rising
into light winds created by waves as
revolutionary.
unlikely.
unassailable.
probable.
3. According to the text, the skeleton of a pterosaur can be distinguished
from that of a bird by the
size of its wingspan.
presence of hollow spaces in its bones.
anatomic origin of its wing strut.
presence of hooklike projections on its hind feet.
4. The ideas attributed to T. H. Huxley in the text suggest that he would
most likely agree with which of the following statements?
An animal’s brain size has little bearing on its ability to master
complex behaviors.
An animal’s appearance is often influenced by environmental
requirements and physical capabilities.
Animals within a given family group are unlikely to change their
appearance dramatically over a period of time.
The origin of flight in vertebrates was an accidental development
rather than the outcome of specialization or adaptation.
5. Which of the following best describes the organization of the last
paragraph of the text?
New evidence is introduced to support a traditional point of view.
Three explanations for a phenomenon are presented and each is disputed
by means of specific information.
Three hypotheses are outlined and evidence supporting each is
given.
Recent discoveries are described and their implications for future
study are projected.
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