Sugar is a different concept from Flour. Flour is a type of Convert. 
Road is related to House. you are likely to find Ceiling in/at/on House. you are likely to find Ceiling in/at/on Classroom. 
Sugar <--DistinctFrom--> Flour --IsA--> Convert 
Road <--RelatedTo--> House <--AtLocation-- Ceiling --AtLocation--> Classroom 