再问gwd8-3

For protection from the summer sun, the Mojave lived in open-sided, flat-topped dwellings known as shades, each a roof of poles and arrow
            weed supported by posts set in a rectangle.

A.      each a roof of poles and arrowweed

B.       each a roof of poles and arrowweed that are being

C.      with each being a roof of poles and arrowweed

D.      with roofs of poles and arrowweed to be

E.       with roofs of poles and arrowweed that are

首先，我不懂这句话的意思。、选a是不是有点类似刘振明《语法精解》中的先讲全体性质，后来个体特征的那种阿。all....,each...

为了躲避阳光，M住在四周敞开，平屋顶的住宅中，也就是所谓的shades，每一个shade的屋顶都是用pole和arrowweed做成，并且由按四边形排列的立柱支撑。

太牛了。谢谢你给我解答这么多问题。呵呵