GWD有题不懂~请教

傻熊有傻福

For protection from the summer sun, the Mojave lived in open-sided, flat-topped dwellings known as shades, each a roof of poles and arrowweed 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

答案是A，each a...?

kaolajiayou

先排除CDE    方法1前呼后应的结构更像标准答案，前面说了房子，后面接着说roofA B 好，
            方法2逗号+with 会让人不知道修饰谁

ＡＢ比较　  Ｂ多加了个that are being 一举

所以选A