ShehasneverbeentotheGreatWallbefore.Todayshesawit___thefirsttime.A.atB.forC.inD.
ShehasneverbeentotheGreatWallbefore.Todayshesawit___thefirsttime.
A.atB.forC.inD.by
答案是选B,但我想知道A为什么不对.
还有就是这四个选项中的短语都成立吗,如果成立的话该怎么用呢?请分别说明,