The ancient Anasazi harvested such native desert vegetation as the purple-flowered bee plant, what they now commonly call wild spinach in northern Arizona and other parts of the southwestern United States.
A what they now commonly call
B a plant that they now commonly call
C now commonly called
D and is now commonly called
E which it is now commonly called
答案C
此题C选项： 如果是定语从句 which is now commonly called，which is可以省略？
D选项 and is 也不对，and前后平行的话，需要加主语那种植物，如果不加这个植物的主语，那is的主语就变成了and前面那半句话的主语Anasazi了，Anasazi不能是菠菜啊 （或者说，D选项这种省略and后半句的主语所带来的伤害 比C选项省略which is带来的伤害大的多的多，实属硬伤 ）
至于E，如果要用非限制性定语的形式，which前面有逗号，有个purple-flowered bee plant，权且OK吧，但which后面跟了个 it 就不对了啊，这也是硬伤