（1）Gauss was able to show by a theoretical analysis that the field arose within the solid earth ... [北大《英语》(三), p. 101]
[原译]高斯通过理论分析能够证明场是在地球实体内产生的……(教参)
(2) After years of difficulty, Whittle was, however, able to build his first engine. [清华大学《英语教程》(三), p. 163]
[原译]经过几年的艰苦努力，怀特终于能够制造出他的第一台发动机。（教参）
(3) Many of the materials listed above as examples of organic compounds were once believed to be products of living organisms — and so were called organic. Following much laboratory experimentation, however, chemists were able to demonstrate that certain products, which had previously been considered the results of vital or living processes, could be produced in the laboratory.
[原译]上面作为有机化合物的例子列举的许多物质,曾一度被认为是有生命的生物的产物,所以称作有机的。然而,在进行了许多实验室实验以后,化学家们能够证明,以前认为是生命过程产物的某些物品,却是可以在实验室制造出来的。(《科技英语的理解与翻译》,p.20)
根据我的汉语语感我觉得上列诸译文中打着重号的部分有点不对味儿。但毛病出在什么地方呢？我又说不出来。
以上各句把 was/were able to 一律译成“能够”，是不尽妥当的。例(1)、(2)、(3)中的 was/were able to + infinitive，似可以分别译作“……（终于）证明了”“……终于制造出了”“……证明了……”。
请做下面的英语试题：
- Humans living in the Pleistocene epoch survived in part because they are able to form into
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He confessed that for months he was scarcely being able to look at the lawyer without becoming angry. (TOEFL)
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Biologists are predicting that they have been able to alter genes and control heredity. (TOEFL)