Directions:
You have 20 minutes to plan and write your response. Your response will be judged on the basis of the quality of your writing and on how well your response presents the points in the lecture and their relationship to the reading passage. Typically an effective response will be 150 to 225 words.
Question:Summarize the points made in the lecture, being sure to explain how they cast doubt on the specific points made in the reading passage.
写作原文
Pterosaurs were an ancient group of winged reptiles that lived alongside the dinosaurs. Many pterosaurs were very large, some as large as a giraffe and with a wingspan of over 12 meters. Paleontologists have long wondered whether large pterosaurs were capable of powered flight (flying by flapping their wings) or whether they were able only to glide. Several arguments have been made against powered flight. Doubters point out that since modern reptiles are cold-blooded, ancient reptiles such as pterosaurs were probably cold-blooded as well. Cold-blooded animals typically have a slow metabolism and are unable to produce a lot of energy. Powered flight is an activity requiring a lot of energy, which is why all modern vertebrates that fly are warm-blooded, not cold-blooded. It seemed unlikely that pterosaurs would have been able to generate the energy needed to fly.
Second, there is a limit to the weight of animals that can be kept airborne by powered flight. Pterosaurs that were as large as a giraffe were probably so heavy that they would not have been able to flap their wings fast enough to stay aloft for any length of time.
Third, all animals with powered flight are able to take off from the ground. For example, birds take off by jumping from their legs or running to gain speed and then jumping. But these methods would not have worked for large pterosaurs. Large pterosaurs would have needed big, powerful muscles in their back legs to launch themselves into the air, and we know from fossilized bones that their back leg muscles were too small and weak to allow the pterosaurs to run fast enough or jump high enough to launch themselves into the air.
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总耗时: 27 m 57 s
word Count: 310
the article and the lecture both deal with the characters of the pterosaurs are actually could blooded animals or not. while the author of the article feels doubt about whether the pterosaurs are reptiles or not, for three specific reasons, the lecturer opposes the author's claims. her position is that pterosaurs are reptiles.
first of all, according to the writer, cold-blooded animals have a slow metabolism which demonstrate that it produced low energy. But in the case of pterosaurs, they required lots of energy to fly. furthermore, it is stated in the article that modern vertebrates which are warm-blooded can fly instead of cold-blooded. however, the lecturer disputes this point. she claims that pterosaurs have heavy feathers which completely covered their body. additionally, they maintain their body warm as warm-blooded animals, ao that pterosaurs produced enough energy to fly.
secondly, the author states that pterosaurs have heavy wings giraffes as large. on top of that, he adds that so unable to flap their wings and stay long. nevertheless, the lecturer refutes this specific argument. the lecturer asserts that the pterosaur's bones are hollow. so hollow body not heavy as their size. further, she points out that pterosaurs easily flap their wings.
finally, the writer posits that birds take off by pumping and running from their legs but pterosaurs have large bodies and from their fossils, their legs are too small and weak to run and jump. as opposed to the author, the lecturer holds that pterosaurs have four legs so they did not need to force only backward legs. she goes on to say that for these reason pterosaurs easily fly. moreover she believes that pterosaurs are reptiles with cold-blooded.
in conclusion, although the reading and the lecturer are both about the body structure of pterosaurs, the three main points made in the reading are effectively challenged by the lectureer.
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