GRE阅读文章的第二种常见结构是“新老观点对比型”。 这类文章在开始提出老观点,然后提出新观点并进行论述。通常新观点是文章的主题。老观点出现的标志词有:
1. 传统观点: has been, traditionally, until recently等
2. 大众观点:frequently, widely, many等
新观点出现的标志词有:however, recently, now等。
例如,
Traditionally, pollination by wind has been viewed as a reproductive process marked by random events in which the vagaries of the wind are compensated for by the generation of vast quantities of pollen, so that the ultimate production of new seeds is assured at the expense of producing much more pollen than is actually used.
However, a number of features that are characteristic of wind-pollinated plants reduce pollen waste….
文章首句指出:“传统上,风媒授粉过程一直被视为是一个以随机事件为标志的繁殖过程,其中风的不确定性通过产生大量花粉而得以补偿,因此,新种子的最终繁殖得以保证,而此举的代价是所需产生的花粉要远远超过实际的使用量。”由第一个词traditionally可知文章首句为老观点(由于风的不确定性,风媒植物要产生大量花粉补偿),那么本文的结构是“新老观点对比型”。
第二段首句出现了GRE阅读中的标志性转折词however,说明这句话就是新观点:“但是,风媒植物所独有的一系列特征可减少花粉浪费。”这说明风媒植物除了可以产生大量花粉加以补偿的消极策略之外,还可以通过一些积极机制减少花粉损失,不一定需要产生大量花粉。