Before(在······之前)在他把车开进山里之前,你得设法把他的卡车拦截住。Youshould nail histruckbefore he drives up the mountains By ( 在······之前)你必须在10点完成You have to finish it by 10. ago(以前,以往)十年前,我还是这里的霸主。Ten years ago I am still the overlord here. Ahead of (领先,在······之前)我必须走在他们前头。I must go ahead of them.