35．In agriculture，the transformation was marked by the emergence of the grainelevators，the cottonpresses，thewarehouses，and thecommodity exchangesthat seemed to so many of thenation's farmers the visible sign of a vast conspiracy against them．

(特殊结构marked by；定语从句that seemed…the visible sign…)

在农业上，这一变化的标志是谷物升降机、皮棉打包机厂、货栈和商品交换的出现,对全国的众多农民来说它们是反对农民的大阴谋的明显标志。

分句1：In agriculture，the transformation was marked bythe emergence of the grain elevators，the cotton presses，the warehouses，and the commodity exchanges

分句2：that seemed to so many of thenation's farmers the visible sign of a vast conspiracy against them

分句1是整个长句子的主句，其中宾语部分是由几个并列短语构成的

分句2是分句1的定语从句，进一步解释了这些东西何以成为了“标志”

1和2嵌套