by the time he arrives in beijing ,we ___here for two days

问题描述:

by the time he arrives in beijing ,we ___here for two days
A will have stayed B have been staying

前面是用的一般现在时态哦~
所以这里可以解释成对未来的猜测~
就是当他达到北京的那个时候,我们应该已经在这里呆了2天了~
是对未来情况的预测~
不明白的再问哟,请及时采纳,多谢!那B选项呢现在完成进行时~一般强调一个动作在一段时间内重复发生~