How did you know him?we___on the train to guangzhou in 1999 and we ___friends for ten years
问题描述：
How did you know him?we___on the train to guangzhou in 1999 and we ___friends for ten years
How did you know him?
we _met 、 have met 还是 had met__ on the train to guangzhou in 1999 and we _have been 还是had been__friends for ten years.
要用什么时态啊?
答
How did you know him?
we meton the train to guangzhou in 1999 and we have been friends for ten years.后面那个为什么不用过去完成时啊？for ten years可以看出,have been表示朋友关系持续到现在。