Ski is related to Slope. Slope is related to Necessity. 
you are likely to find Teaspoon in/at/on Kitchen. you are likely to find Cover in/at/on Kitchen. Cover is related to Table. you are likely to find Table in/at/on Building. 
Ski <--RelatedTo--> Slope <--RelatedTo--> Necessity 
Teaspoon --AtLocation--> Kitchen <--AtLocation-- Cover <--RelatedTo--> Table --AtLocation--> Building 