题目选项分析

The Chicago and Calumet Rivers, originally flowing into the St. Lawrence by way of Lake Michigan, have been redirected through the construction of canals so that the water now empties into the Mississippi by way of the Illinois River.

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