at the floor 和on the floor的区别?

the ground floor 和the first floor 的区别 On just()at the floor! 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? at the first floor还是on the first floor at the second floor 还是on the second floor a book on the floor 和 a book is on the floor有什么区别? on the floor与on the ground的区别? in the first floor和on the first floor有什么区别 in the second floor与on the second floor的区别,谢谢T-T： sweep the floor和 mop the floor 区别 On The Floor 歌词