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 - was banked with dirt as high as
- 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！ | 
