be back用法

be back用法 be back ,come back和go back 的用法区别. It will be some time until Bill came back.until用法, I am sad to be here watching you all heading back home 句中watching用法 be back的用法看到书上是you are to be back by 9 o'clock那you are back by 9 o'clock可以吗?这里的BACK应该是副词吧? be back in be back at 区别 we will be back 能用we will back 后者的用法对吗?为什么要加个“be”呢?解释清楚一点可是back在作后退,回来解释时可以做动词啊,为什么还要加be呢? 请问back.come back.be back在用法上有何区别?它们之间可以互换吗?例如：1.it's september,we are all back at school.2.when did you come back.3.what do you usually come back?4.he will be back in a month.请说明一下这些句子. 以下两个句子的be的用法He will be in his small boat,Topsail.He will be away for two mouths.请解释一下这两个be的用法和在什么情况下需要这样用.he has not be back yet,he will be back ten minutes.he has not back yet ,里面 Be back soon U'll be back “I will be back! Be back home I'll be back be traced back to 用 be back 造句 WE WILL BE BACK We will be back!