PREP169有疑问.....NN路过看看

169. The Chicago and Calumet
            Rivers originally flowed into the St. Lawrence by way of Lake Michigan, but having been redirected by constructing canals so that the water now empties into the Mississippi by way of the Illinois River.

A. Rivers originally flowed into the St. Lawrence by way of Lake Michigan, but having been redirected by constructing

B. Rivers had originally flowed into the St. Lawrence by way of Lake Michigan, but they have been redirected by constructing

C. Rivers, which originally flowed into the St. Lawrence by way of Lake Michigan but have been redirected by the construction of

D. Rivers, originally flowing into the St. Lawrence by way of Lake Michigan, but having been redirected by the construction of

E. Rivers, originally flowing into the St. Lawrence by way of Lake Michigan, have been redirected through the construction of

 这题选E是没有问题的,因为A用HAVING BEEN 不恰当

B用HAD ORIGINALLY不当

C中没谓语

D也没谓语

1.E虽然勉强过关,但是因为ORIGINALLY是应该用一般过去时吧....在BY上好象看过,但具体在哪忘了...问NN,选E还有其他理由吗?

2.E是不是存在我刚才说的问题呀?3Q

个人观点

GMAT是挑错，不是选对。

很多正确答案并不一定是最正确的，但是是相对而言最好的。

非要问选E的原因，那就是他没有致命的错误。时态啊句式啊都是正确的。

不要记by的那些很硬性的规矩，具体情况具体分析。