动词时态的四种用法答:时间状语从句,条件句中,从句用一般现在时代替将来时When,while,before,after,till,once,as soon as,so long as,by the time,if,in case (that),unless,even if,whether,the moment,the minute,the day,the year,immediatelyHe is going to visit her aunt the day he arrives in Beijing.他一到北京,就...