★★★

文章分析：

Blurb给出了文章的研究主题以及两个相关理论。

para 1: 引出研究背景及研究人员，并点出研究目的（因为有学生质疑，所以设计研究项目观察小鸟如何学飞）；

para 2: 研究实验的设置及调整（中发生的故事）；

Chukar Partridge 石鸡

incredulous

para 3: 实验结果（小鸟“手脚”并用）；

para 4: 新的实验以及结果（鸟挥动翅膀是为了增加抓地力）；

spoiler 车的尾翼

Formula One racing

尾翼的空气动力学 aerodynamic

para 5: 给出定义，实验拓展及延伸（不仅小鸟如此，成鸟也一样）；

para 6: 最终结论，WAIR弥补了blurb中提到的两种理论的不足。

line 70 with one fell swoop

If you do something in one fell swoop that means you did it in a single action. This phrase can also mean that something was done quickly; a swift action.

Example: My yard was a mess. The grass was overgrown and weeds were popping up everywhere! To solve the problem, I brought out my nifty lawnmower and in one fell swoop I restored my lawn back to a presentable condition.

题型解析：

21 D 结构题的篇章结构

22 A 单词意思题

dare 

dispute: argue about sth. ; discuss heatedly; compete for

23 A 间接细节（假设题）

这一题值得一说。

assumption就是实验设置的大前提，前提成立，这个实验才有做的可能。

那对于做题，我们可以用“取反选项，实验就变得没有意义”来确定正确答案。

而错误答案即使取反，对于实验也没啥大的影响。

这是这一题的解题思路，到GRE层面还是会考的。

不过这一题错，还有一层是A里的表达不认识：

shed light on ... 阐明，解释清楚

这一题虽然难，但是可以用排除法及下一题循证来辅助解决。

24 B 上一题的定位

大前提肯定就出现在实验原理、背景的地方了。也就是para 2的位置。

25 C 结构题之信息目的

26 C 直接细节

27 B 直接细节

28 B 单词意思题

29 D 间接细节

30 D 上一题定位

作者简介：

Thor Hanson - Author & Biologist

Dr. Thor Hanson is a Guggenheim Fellow, a Switzer Environmental Fellow, and an award winning author and biologist.  His books include Buzz, The Triumph of Seeds, The Impenetrable Forest, Feathers, and the illustrated children's favorite, Bartholomew Quill.  Hanson's writing has been translated into more than ten languages and has earned many accolades, including The John Burroughs Medal, the Phi Beta Kappa Award, the AAAS/Subaru SB&F Prize, and three Pacific Northwest Book Awards. He co-hosted the PBS Nature series American Spring Live, and he has appeared as a guest on many other programs, including  NPR's Fresh Air, Science Friday, To the Best of Our Knowledge, and On Point, as well as The Current on CBC, and Book Lust with Nancy Pearl.  Hanson lives with his wife and son on an island in the Pacific Northwest. 

For more info: 

https://www.thorhanson.net/