【小站原创】TPO42托福阅读文本及答案解析（Explaining Dinosaur Extinction）
- 2016年05月16日10:54 来源：小站教育作者：小站托福编辑
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Explaining Dinosaur extinction
Dinosaurs rapidly became extinct about 65 million years ago as part of a mass extinction known as the K-T event, because it is associated with a geological signature known as the K-T boundary, usually a thin band of sedimentation found in various parts of the world (K is the traditional abbreviation for the Cretaceous, derived from the German name Kreidezeit). Many explanations have been proposed for why dinosaurs became extinct. For example, some have blamed dinosaur extinction on the development of flowering plants, which were supposedly more difficult to digest and could have caused constipation or indigestion—except that flowering plants first evolved in the Early Cretaceous, about 60 million years before the dinosaurs died out. In fact, several scientists have suggested that the duckbill dinosaurs and homed dinosaurs, with their complex battery of grinding teeth, evolved to exploit this new resource of rapidly growing flowering plants Others have blamed extinction on competition from the mammals, which allegedly ate all the dinosaur eggs—except that mammals and dinosaurs appeared at the same time in the Late Triassic, about 190 million years ago, and there is no reason to believe that mammals suddenly acquired a taste for dinosaur eggs after 120 million years of coexistence Some explanations (such as the one stating that dinosaurs all died of diseases) fail because there is no way to scientifically test them, and they cannot move beyond the realm of speculation and guesswork.
1. In paragraph 1, why does the author include a discussion of when flowering plants evolved?
A. To help explain why some scientists believe that the development of flowering plants led to dinosaur extinction
B. To cast doubt on the theory that the development of flowering plants caused dinosaurs to become extinct
D. To emphasize that duckbill dinosaurs and horned dinosaurs were the first dinosaurs to become extinct
解析：根据flowering plants evolved定位至except that flowering plants first evolved in the Early Cretaceous, 看其前面一句话Many explanations have been proposed for why dinosaurs became extinct. For example, some have blamed dinosaur extinction on the development of flowering plants,作者提及开花植物的原因就是为了怀疑一些说开花植物导致恐龙灭绝的理论，所以可知B选项正确。