Many prehistorians believe that farming may have emerged dependently in several different areas of the world when small communities, driven by increasing population and a decline in available food resources, began to plant seeds in the ground in an effort to guarantee their survival. (TPO33, 44)

　　大家自己先读，不回读，看一遍是否能理解

　　Many prehistorians believe that farming may have emerged dependently (in several different areas of the world) (when small communities, (driven by increasing population and a decline in available food resources), began to plant seeds in the ground in an effort to guarantee their survival). (TPO33, 44)

　　托福阅读长难句100句分析：

　　这个句子的主干是：

　　Many prehistorians believe that从句

　　从句中的主干是：

　　farming may have emerged dependently

　　修饰一：(in several different areas of the world)，介词短语

　　中文：在世界几个不同地区

　　修饰二：(driven by increasing population and a decline inavailable food resources)，非谓语动词，相当于形容词修饰small communities

　　中文：迫于人口不断增长和可用食物资源减少

　　修饰三：(when small communities began to plant seeds in the ground in an effort to guarantee their survival)，从句

　　大家一定要注意这里的断句问题!!!

　　从句的主谓被非谓语给隔开了。就是它：

　　(driven by increasing population and a decline inavailable food resources)

　　中文：当一些小的群落开始在地里种植种子去努力保证他们生存时

　　托福阅读长难句100句参考翻译：

　　许多史前学家认为：当一些小的群落迫于人口不断增长和可用食物资源减少压力，开始在地里种植种子去努力保证他们生存时，农业可能在世界几个不同地区就独立出现了。

　　这个句子的主要修饰成分就是非谓语动词、介词短语和从句，大家务必想清楚，每一个修饰成分修饰的是什么，才能看清楚这个句子的结构。