逗号+过去分词的用途

想請教各位NN，逗號+過去分詞的用途為何? 和逗號+現在分詞的用途一樣表示伴隨狀語嗎? 表示前一個獨立子句的後續動作嗎? 有例題如下:

Asset allocators create portfolios, often in the form of mutual funds, with the intention to turn in good results in both “bull” and “bear” markets.

(A)   with the intention

(B)   the intention of which is

(C)   intended

(D)   and intending

(E)    so intended as

Ans--(C)

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

Ans--(B)

麻煩大家了~ 謝謝!

Q2: 从划线部分起到句尾可以简化为 ... structures, ..., connected by ... roads

connected by roads 是用来修饰structures的，不用加to be，所以A, C, E排除。另外原句强调的是每个structure有up to 600 rooms，所以each要紧跟up to 600 rooms，否则就变成75个structure总共有600个room了，这样就称不上是spectacular scale － 所以D也排除。

that's my 2cents.

逗号＋ing可以表伴随状态，也可修饰前面的部分；逗号＋ed只能修饰前面部分，不能起到表伴随状态的作用。

请NN指正，谢谢！

顶！

同问！

另外，第二个问题句中的, of up to 600 rooms each,   是插入语吗？

第一个问题,intended是动词,全句的谓语.

第二个问题,我同意2楼的看法.3楼的问题,ing一般修饰前面的动作,不能做定语.

第一題的intended應該不是動詞吧? 動詞應該是create... intended是過去分詞吧?