一个月前 a month ago ; one month prior ; A month ago he received ; Civil

一月前 A MONTH AGO

直到一个月前 Up to one month ago

一个月前的今天 this day month

之前一个月 One month before ; Previous month ; One month prior

前一个月 one month prior

一个月前了 A month ago the

他收到了一个月前 A month ago he received

在一个月前就开始准备 Start preparing a month ago