PREP, 1-41

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A，

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.做独立主格结构

its framework--overlaid~~~~~and banked.