break up 作为动词短语，If someone who is talking on a mobile phone is breaking up, their voice can no longer be heard clearly. 表示（打电话）听不清，声音断断续续。
扩展：UK表达，When schools and colleges, or the teachers and students who go to them break up, their classes stop and the holidays start .这时break up表示（学校）放假。

【例句】
We broke up for the holidays in June.
我们6月份放假。

The line's gone; I think you're breaking up.
掉线了；我听不清你说什么。