题目选项分析

For protection from the summer sun, the Mojave lived in open-sided, flat-topped dwellings known as shades, with each being a roof of poles and arrow weed supported by posts set in a rectangle.

For protection from the summer sun, the Mojave lived in open-sided, flat-topped dwellings known as shades, each a roof of poles and arrow weed supported by posts set in a rectangle.