GWD10-14

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

4. was banked with dirt as high as
5. was banked with dirt as high as that of

the house ......was ....., its framework overlaid, and banked....

这是两个句子，但没有任何连接词，怎么回事？

请大牛指点！

因为后面是独立主格结构

banked
adj.
积起的, 堆积的

n.+a./doing/done为独立主格结构。

我是这样理解的：

由于划线前有and，而选项均为banked/was banked，而非和shape，framework平行

若为was banked则为谓语，逻辑意思不合理

故为overlaid//banked作framework的定语,its framework 做 shape的 同位语 ，期待 nn指正～～