新prep1--77 结构问题~ 请教高人！！！

cynthia627

77.   (28625-!-item-!-188;#058&004000)

The Anasazi settlements at Chaco Canyon were built on a spectacular scale with more than 75 carefully engineered structures, of up to 600 rooms each, were connected by a complex regional system of roads.

(A) with more than 75 carefully engineered structures, of up to 600 rooms each, were

(B) with more than 75 carefully engineered structures, of up to 600 rooms each,

(C) of more than 75 carefully engineered structures of up to 600 rooms, each that had been

(D) of more than 75 carefully engineered structures of up to 600 rooms and with each

(E) of more than 75 carefully engineered structures of up to 600 rooms, each had been

OMA：B

其实，这道题我每次做也没做错过。所以一直都没怎么注意他。然而今天发现，其实我还真是不大明白这个结构~ 我想请教各位这里面的of是从哪里来的呢？谢谢大家~

awishtosuccess

mark.

yhwut

connected by a complex regional system of roads 分词后置定语修饰structures
of up to 600 rooms each插入成分可以提前，修饰The Anasazi settlements