TPO 4
阅读解析与听力预测
总论：
恐龙是endotherms。
正文将用三个理由支持这个观点，所以是典型的观点理由型文章，听听力时应该注意是反驳理由还是反驳逻辑。
理由1：
在极地发现恐龙化石，只有恒温动物才应该能生活在极地。
理由2：
腿长在身下，而不是两侧，说明腿是恒温动物用来跑步的。
理由3：
有Haversian canals，而只有恒温动物才有。
听力解析
don't…prove…endotherms是废话，不需要记。
polar dinosaur argument，说明进入第一点。polar… warmer than today，已经把反驳说清楚了，那会儿极地暖和，不恒温也能住。warm enough…part of the year for…not endotherms…这是废话。During months cold，migrate or hibernate，完美解决了恐龙当年的生存。doesn't prove…endotherms是废话。
♦ 本段逻辑梳理：就算有极地恐龙，也不需要恒温，因为当年极地暖和，一年里某些时候恐龙就可以生存在那儿，冷了迁徙或冬眠就可以了。
whatabout…legs placedunder…，进入第二点。doesn't…mean… high-energy endotherms builtfor running，是废话。another explanation是空话。supports moreweight，so…cangrow toavery large size，解释清楚了，腿在下面，不是为了跑得快，而是为了体积大。Being large had advantages，体积大就是好处。so we don't need…endotherm or running to explain，这是废话。
♦ 本段逻辑梳理：腿长在下面也不代表是需要长时间跑步的恒温动物，因为腿在下面可以支撑大的身体，这对恐龙就足够有益。
how about bone structure，提示进入第三点。do have Haversian canals，让步，接下来肯定反驳。also have growth rings，这个growth rings不用听肯定知道不符合endotherms，而符合non-endotherms。…thickening of the bone that indicates periods of time when the dinosaurs were not rapidly growing，这个rings体现了恐龙停止生长的时期。evidence that dinosaurs stopped growing or grew more slowly during cooler periods. This pattern of periodic growth…characteristic of…not endotherms，说得非常清楚了，这个rings表明恐龙生长有周期性，冷天长得慢，热天长得快，而只有non-endotherms才这样。Animals…maintain a constant body temperature…grow rapidly even when…cool，恒温动物什么时候都长，这是废话。
♦ 本段逻辑梳理：就算恐龙有H canals，恐龙还有growth rings，说明它们冷天不长，热天长，而只有非恒温动物才这样。
满分范文
The article presents three arguments why dinosaurs were endotherms，all of which are questioned by the lecturer.
For starters，the lecturer believes that the discovery of dinosaur fossils in polar regions does not entail that dinosaurs were endotherms.Because polar regions back at that time were much warmer than they are today，for some period of the year，the temperature could be warm enough for dinosaurs to survive there even if they were not able to adjust their body temperature.For the cooler time，dinosaurs could simply migrate or hibernate.
Second，the lecturer argues that dinosaurs could well be non-endotherms while still having legs growing underneath their bodies. The leg position does not have to be explained by intense running，as in the case of endotherms;instead，it could alternatively help sustain a larger and heavier body，which could provide survival advantage for dinosaurs.
Last, even though dinosaurs do have Haversian canals, which typically belong to endotherms, the lecturer points to the discovery of growth rings in dinosaur fossils that suggest a similarity between dinosaurs and non-endotherms. The rings indicate a cycle of fast growth in warm periods followed by little growth during cool periods, a cycle that typically belongs to non-endotherms.