1 . 前
...ers negotiate(協商, 談判) their fares (車票費用)with __6__ before(在…之前) they take a ride/(乘車).
2 . 之前
...ago/last以前/最后before之前指示代詞.
3 . 以前
... when(當…時), while(當…時), as (當…時),as soon as (一…就), before(在…以前), after(在…以后), since(自…以來), till(直到…), until(直到…).
4 . 面前
The long night is beforeme , and I am tired., 在我面前的是漫漫的長夜 , 我疲倦了.