GRE阅读理解的文章可有两种分类的方法。
按照文章的题材分类:gre文章有4种类型
* 人文学科类:早期以文学评论型为主,对于中国考生来说难度偏高,主要是因为中国考生缺乏相应的人文背景和对英语叙述句式的不习惯。1993年以后,文学评论型文章的难度有极其明显的下降,1996年以后,这种类型的文章更是基本趋向消亡,取而代之的是大量的人文学科中的艺术和人文综合类文章,而且多以短文章出现,叙述简单,题目难度正常,已经不再是中国考生的一块心病。
* 社会科学类:历史、法律、社会学和政治学都有可能涉及,有两点需注意:
1) 近年少有纯学术研究文章,多数谈的是实际的社会问题,如民族、女权问题等。
2)gre文章几乎不涉及经济制度和商业管理,这是为了和GMAT文章明确分工。
* 生命科学类:在早期的gre考试中,这类文章被文科考生视为“洪水猛兽”。好在
1994年后,生命类型的文章逐步舍弃了诸如无氧代谢、基因遗传和人体微循环这样微观而抽象的题材。现在出现的一般是宏观生物学的题材,如动植物习性、生态群落与环境的关系、人类活动与生物圈等。
* 其他自然科学类:除生命科学之外的自然科学题材,如地质、气象、物理、化学、天文等。请注意两点:
1)一般文章所谈及的现象,不具备专业知识也可以看懂。如果所谈专业比较高深,像核物理和宇宙生成说之类,题目往往会偏离主题,改为主要就学科发展史或科学家生平提问。
2)近年来,纯理科内容趋少,关心当前科学实用热点的文章比较多。如环保、新型发明和新型材料等。
从题材来为gre文章分类,看起来很整齐,4篇文章,每篇各占其一,永元例外。但此种外表的美感对我们做题的帮助不大。我们也不能指望把某种题材的背景特意加以复习就可以上场不惧,一劳永逸。这是永无可能的事情,因为,题材的细节几乎不会重考。
按写作方式分类
形形色色的gre文章,绝大多数可分为两种基本写作类型。
1.presentation,即立论型的文章。在此类文章中,作者阐明一个自己提出的观点、理论、解释,没有对立面;或者文章后半段稍有不同意见,但都被作者反驳掉,不足为据。
例文:
the recent, apparently successful, prediction by mathematical models of an appearance of e1 nino—the warm ocean current that periodically develops along the pacific coast of south america—has excited researchers. jacob bjerknes pointed out over 20 years ago how winds might create either abnormally warm or abnormally cold water in the eastern equatorial pacific. nonetheless, until the development of the models no one could explain why conditions should regularly shift from one to the other, as happens in the periodic oscillations between appearances of the warm e1 nino and the cold so-called anti-e1 nino. the answer, at least if the current model that links the behavior of the ocean to that of the atmosphere is correct, is to be found in the ocean.
it has long been known that during an e1 nino, two conditions exist: (1) unusually warm water extends along the eastern pacific, principally along the coasts of ecuador and peru, and (2) winds blow from the west into the warmer air rising over the warm water in the east. these winds tend to create a feedback mechanism by driving the warmer surface water into a “pile” that blocks the normal up-welling of deeper, cold water in the east and further warms the eastern water, thus strengthening the wind still more. the contribution of the model is to show that the winds of an e1 nino, which raise sea level in the east, simultaneously send a signal to the west lowering sea level. according to the model, that signal is generated as a negative rossby wave, a wave of depressed, or negative, sea level, that moves westward parallel to the equator at 25 to 85 kilometers per day. taking months to traverse the pacific, rossby waves march to the western boundary of the pacific basin, which is modeled as a smooth wall but in reality consists of quite irregular island chains, such as the philippines and indonesia. when the waves meet the western boundary, they are reflected, and the model predicts that rossby waves will be broken into numerous coastal kelvin waves carrying the same negative sea-level signal. these eventually shoot toward the equator, and then head eastward along the equator propelled by the rotation of the earth at a speed of about 250 kilometers per day. when enough kelvin waves of sufficient amplitude arrive from the western pacific, their negative sea-level rossby waves westward, waves that will eventually return as cold cycle ending positive kelvin waves, beginning another warming cycle.
此文中,作者始终在说当前预测厄尔尼诺的一个模型是如何地好,优于以前的同类理论,见不到一点其他人的评价。
