如果E对,则the Incan highway was over 2,500 miles long 是主句,The greatest road system built in the Americas prior to the arrival of Christopher Columbus, 和 extending from northern Ecuador through Peru to Southern Chile.是从属部分,做什么成分?各修饰什么?请NN帮忙解释一下,看了众多的XDJM的想法,还是不能说服我选E,我认为B对。 B的逻辑意思完整,在从语法上不能确定的时候,我还是选择逻辑意思完整的吧。