题目内容：

They say that the footprints could have been made by...句中could可用may/might
They say that the footprints could have been made by bears.句中的could可用may/might代替吗?如果有可能请详细解释could和may /might在 表示推测的用法和有什么不同?
cinda96
可以用may or might代替吗?

优质解答

这里的could有猜测的意思,所以用的是过去式,也有一些虚拟的成份