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W1 话题：Biology 生物学 材料要点重现：lecture中教授的观点是翼龙可以飞。原因有三点，第一是翼龙是暖血动物可以产生飞行所需能量。第二是翼龙骨头是空心的所以很轻。第三是翼龙飞行可以用四肢而不只是后肢。 高分词汇：contradict, reptile, cold-blooded, repute, metabolism, aloft, hollow, airborne, flap, launch 范文：In the reading passage, the writer claims that large pterosaurs were incapable of powered flight. The speaker, however, contradicts this view for the following three reasons. First of all, the reading materials points out that ancient reptiles such as pterosaurs were probably cold-blooded and were incapable of producing enough energies for flying. But the speaker reputes that pterosaurs had a dense, hair-like covering which was typical of warm-blooded animals whose metabolism was able to supply the energy required for powered flight. Second, the author states that pterosaurs were too heavy to stay aloft for any length of time. But the lecturer suggests that the bones of pterosaurs were hollow instead of solid. Therefore, although they had large body frames, the pterosaurs' weight was probably low enough to allow them to keep themselves airborne by flapping wings. Lastly, the author indicates pterosaurs lacked the big, powerful muscles in their back legs to run fast enough or jump high enough to launch themselves into the air. Contrary to the reading passage, the speaker emphasizes that unlike birds which used just the back limbs, pterosaurs used four limbs to push off the ground.
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发表于 2018-11-6 11:35:59