OG12th 4 时态纠结

danielgc

of all the vast tides of migration that have swept through history,      maybe none is more concentrated as       the wave that brought 12 million immigrants onto American shores in little more than three decades

A. maybe none is more concentrated as
B. it may be that none is more concentrated as
C. perhaps it is none that is more concentrated than
D. maybe it is none that was more concentrated than
E. perhaps none was more concentrated than


这个“was"让我在读题的时候很不舒服，OG的解释是，因为定语从句中brought用过去式，表是动作已经完成。可是前面为什么”have swept“？没有办法理解这里的时态选择，OG说得也不详细，能给我解释一下吗？谢谢了

danielgc

谢谢你的解答，已经很明白了。只是，作为一个客观事实，在这里能否用一般现在时？

babybearmm

bcd 肯定错 a more 和 as 搭配错
e have swept意思是 从古至今 已经 发生的 移民
所以 对concentrated作比较也应该用过去时 因为都发生在过去
不知道能否信服

danielgc

可不可以改成：Of all the vast tides of migration that swept through history; 主句可不可以写成，maybe none is more concentrated than...如果不可以，哪位告诉我为什么？