Airplane is related to Arrive. Arrive is related to Airport. you are likely to find Bar in/at/on Airport. Bar is a synonym of Prohibit. 
Poster is related to Flag. you are likely to find Flag in/at/on Classroom. 
Airplane <--RelatedTo--> Arrive <--RelatedTo--> Airport <--AtLocation-- Bar <--Synonym--> Prohibit 
Poster <--RelatedTo--> Flag --AtLocation--> Classroom 