She received one month`s salary in advance.

She received one month's salary in advance.

她预支了一个月的工资。

 

介词词组in advance相当于beforehand，意思是：事先；预先。
　　再如：
　　The factory fulfilled the state production plan one month in advance．
　　这个工厂提前一个月完成国家生产计划。