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.
问题描述：
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.
答
九月了,我们都回学校了.be back 表示已经回来了,表示状态.你什么时候回来的. come back 表示回来,指动作.第三句有错.你可以用What time ...若是...