This abundance is notable in Roman settlements (especially urban sites) where the labor that archaeologists have to put into the washing and sorting of potsherds(fragments of pottery) constitutes a high proportion of the total work during the initial phases of excavation.

　　结构划分：

　　This abundance is notable in Roman settlements (especially urban sites) (where the labor (that archaeologists have to put into the washing and sorting of potsherds (fragments of pottery)) constitutes a high proportion of the total work during the initial phases ofexcavation).

　　深度分析：

　　这个句子主干就是：

　　This abundance is notable in Roman settlements

　　这个句子理解的难点在于，where从句里中间有一个定语从句，把the labor和constitute隔开了，大家注意这样一个问题。这个问题只要能够理解，速读就不是问题了。

　　修饰一：(where the labor constitutes a high proportion of the total work during the initial phases of excavation)，从句

　　中文：在这些地方劳动占了挖掘初期总工作量的很高的比例

　　修饰二：(that archaeologists have to put into the washing and sorting of potsherds (fragments of pottery)) ，从句，修饰labor，难点就在于这个从句的理解，其实就是put the labor into the washing and storing of pots herds

　　中文：考古学家花在清洗分类陶瓷碎片上的劳动

　　参考翻译：

　　这种丰富性在罗马居住点(尤其在城市)很明显，在这些地方考古学家花在清洗分类陶瓷碎片上的劳动占了挖掘初期总工作量的很高的比例。