这篇文章讲述了进化evolution与返祖atavism两种现象。按照常理，进化过程中不应该出现倒退throwback的。然而，越来越多的实例可以证明，返祖的确发生，更有可能预示物种的未来。

题目词汇学习

law - 规律，法律，定律

modify - 修改，改变

humpback whale - 座头鲸

exemplify - 例证

controversy - 争议

silent gene - 隐形基因

technical term - 术语

life span - 寿命

amphibian - 双栖动物

ancestor - 祖先

subject - 实验研究对象

lizard - 蜥蜴

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真题再现 Q27 When discussing the theory developed by Louis Dollo, the writer says that

A. it was immediately referred to as Dollo's law

B. it supported the possibility of evolutionary throwbacks.

C. it was modified by biologists in the early twentieth century.

D. it was based on many years of research.

解题思路：

定位词：Louis Dollo, Dollo's law, twentieth century

缘木求鱼，来到原文第三自然段。发现D项的内容没有提及，属于Not Given,不选。而B项的supported跟irreversibility相矛盾，属于False，错项。选项A中的immediately引起质疑，是不是马上就成为一个定律呢？原文用了stuck胶着状态，错项。最后看C.项，根据原文 - 那些biologists ...stating that 没有理由不倒转。这样就跟选项中的modified一词一致，True, 就是它了。