How time flies!Three years _since i became a middle school student.
问题描述:
How time flies!Three years _since i became a middle school student.
A、has passed B、have passed C、passed D、passes
答
A,因为后面有since,所以是从过去到现在.用完成时,然后three years 就是个时间,后面has用单数形式就行了