The medical waste that has fouled beaches in the New York region at the peak of the summer season has taken its toll on business all along the shore, driving vacationers away both from beaches that have been closed and from those that have remained open.

参考答案:

要点：本句主要结构是the medical waste...has taken its toll...。that...season引导定语从句，修饰medical waste。at the peak of the summer season作状语，表时间。driving...是现在分词作状语，表结果。that have been closed和that have remained open是定语从句，分别修饰beaches和those。those代替beaches。

译文：医疗用品生产厂家的废弃物污染了纽约地区的海滨。时值盛夏，一些海滨浴场关闭，而仍然开放的一些海滨浴场也门可罗雀，大批度假者离此而去，这使得海滨地区的商业蒙受严重损失。