Peter is from the UK and is traveling in the US. Now he is looking for a toilet in a mall. He asked a waitress, “Could you tell me where is the men’s room?” “It is at the first floor”, he was answered. He went upstairs and found its women’s room.

在英式英语里 ground floor 是指紧贴地面的那个楼层。它上面的一层叫做 first floor。 在美式英语中，first floor 是指紧贴地面的楼层，它上面的一层是 second floor.