阅读理解的技巧中非常重要的一点是在阅读中迅速地抓住文章或段落的中心思想。

段落的构成有其内在的规律，其中心思想往往是通过段落中的主题句来体现的。因此了解并掌握这些规律，迅速找出主题句，

从而抓住中心思想对于提高阅读理解能力大有益处。

这些规律主要是通过主题句在段落中所处的不同的位置体现的。因此同学们首先应对以下四种段型有所了解，然后通过一系列有意识的训练掌握它们。

1.首句是主题句的规律

①给予例证、解释或说明的段落;

②下定义的段落;

③对两个或两个以上的事物作比较或对比的段落;

④表明原因和结果(往往结果交代在前)的段落。

主题句是首句的段落总是用演绎法撰写，遵循从一般到个别或特殊的写作程序，即以概述开段，随之辅以细说。这样的段落在文章中出现得最多，据专门研究阅读理论与技巧的专家们统计，概率达到70%。请看下例：

People who talk and sing to plants have no mental problems at all, according to an agricultural expert. "In fact, singing and talking to plants makes them grow better," says Dr Braymar. The reason is quite simple. When we sing or talk to plants, we exhale(呼出) CO2 which plants need to survive (continue to live)and grow better. Plants absorb (take in) CO2 through their pores(小孔) during the sunlight hours and produce oxygen which people to survive. Singing and talking have good effect on plants, however, only during the daytime. Singing or talking at bedtime will not help plants to grow better or grow faster.

本段的首句是主题句，其后的句子或是解释说明“对植物说话或唱歌有益于植物”，或是为这一主题思想提供论据。本段的结尾句呼应主题句，在给予主题思想又一论据的同时，幽默地收尾。