题目内容：

we_____each other for ten years.这里填have known 为什么不能填have been knowing

优质解答

we_____each other for ten years.这里填have known 为什么不能填have been knowing因为【have known】是现在完成时,表【认识以后的结果,截止现在“已经10年”】.【have been knowing】是现在完成进行时,表【knowing...