大全690，没被问过，郁闷中。。。

The argument that the dominant form of family structure today is not the nuclear family, but rather it is a family which is modified and extended, is based on a number of facts: the existence of three-generational families, the amount of vertical and horizontal communication between family subunits, and the extent to which family members offer assistance to one another.

(A) family, but rather it is a family which is modified and extended, is based on a number of facts: the existence of three-generational families

(B) family, but is instead a family that is modified and extended, is based on a number of facts: three-generational families exist

(C) family, which has been modified and extended, is based on a number of facts: the existence of three-generational families

(D) family but a modified extended family is based on a number of facts: the existence of three-generational families

(E) family, but also a modified and extended family, is based on a number of facts: three-generational families exist

答案是D ，我不明白的是not.....but ....不是遵循的平行结构吗？ 但题中的not后面的nuclear family 是做表语，but 后面的extended family 是做主语，前后句子结构不平行， 怎么回事？ NN们帮忙啊

感谢ING

感谢ING