in the second floor 与 on the second floor有什么区别?

in the second floor 与 on the second floor有什么区别? 请问on the second floor 与 at the second floor 有什么区别? on the second floor 与 at the second floor 有什么区别? in the second floor与on the second floor的区别,谢谢T-T： on the second floor用什么提问 at the second floor 还是on the second floor floor is the on restaurant the second Were you on the second floor? I live on the second floor. 对on the second floor 提问 It's on the second floor. he lives on the second floor.就second划线提问、