Two years has _____ _____(流逝) before we knew it.

问题描述:

Two years has _____ _____(流逝) before we knew it.

Two years had (gone by )(流逝) before we knew it.
我认为has 应该是had ( 即过去完成时,动作发生在KNEW 前)
加油!不明白再问!