一道时态语法题，大家来看看怎么选？

naon

It is possible that the Roma people have migrated from India across Europe over the course of several centuries that were characterized by this type of nomadic wandering.

A。 have migrated from India across Europe over the course of several centuries that were characterized  
B。 had migrated from India across Europe over the course of several centuries that were characterized  
C。 migrated from India across Europe over the course of several centuries that had been characterized  
D。 migrated from India across Europe over the course of several centuries that were characterized  
E。migrated from India over the course of several centuries that were characterized across Europe  

Augustus8

我选D，
A项现在完成时 对现在造成的影响或结果或表示过去的动作或状态持续到现在，显然Rome人migrate对现在没影响，且没持续到现在
B项过去完成时无时间参照点错
C项逻辑错，在migrate之前就characterize,应该是先migrate后characterize
E项改变句子intended meaning
理解不对的地方望改正

naon

Augustus8 发表于 2016-7-22 19:40
我选D，
A项现在完成时 对现在造成的影响或结果或表示过去的动作或状态持续到现在，显然Rome人migrate对现 ...

正确答案就是D，我刚开始选错了，选成了B，总觉得Over the course of 是个完成时态的标志，后来琢磨了一下，全句中唯一一个一般过去时是were characterized， 这件事是发生在migrate之后的，所以不能作had migrated的过去语境，我觉得你对选项的分析很到位