Seventy percent of the students here( )from the countryside A is B are C comes D has come

问题描述:

Seventy percent of the students here( )from the countryside A is B are C comes D has come
Seventy percent of the students here( )from the countryside
A is B are C comes D has come
请说下理由

B
A要用复数 不行
C不能用单数
D没必要用完成时
空中填are 和 come 都可以