prep的一道改错，29号考试了，麻烦大家给我看看，谢谢

徐小鱼

?The single-family house constructed by the Yana, a Native American people who lived in what is now northern California, was conical in shape, its framework of poles overlaid with slabs of bark, either cedar or pine, and banked with dirt to a height of three to four feet.
?(A) banked with dirt to a height of
?(B) banked with dirt as high as that of
?(C) banked them with dirt to a height of
?(D) was banked with dirt as high as
?(E) was banked with dirt as high as that of
我选了D，请问什么时候该省略AND前后的助动词，BE动词。

ruimiss

不是这样的。
这句its framework of poles overlaid with slabs of bark, either cedar or pine, and banked with dirt to a height of three to four feet.是独立的，解释之前一句。因而， banked with这里是和 overlaid with 平行，所以不要was。还有to a height of 是固定搭配

徐小鱼

原来是这样，谢谢楼上的nn