Vacuum is related to Dirt. Dirt is related to Rock. you are likely to find Rock in/at/on Bridge. you are likely to find Air in/at/on Bridge. 
Sort is a type of Similarity. Sort is a synonym of Description. Description is related to Recent. 
Vacuum <--RelatedTo--> Dirt <--RelatedTo--> Rock --AtLocation--> Bridge <--AtLocation-- Air 
Similarity <--IsA-- Sort <--Synonym--> Description <--RelatedTo--> Recent 