you are likely to find Milk in/at/on Refrigerator. Milk is related to Addition. Addition is related to Cream. 
you are likely to find Beer in/at/on Boat. you are likely to find Relief in/at/on Beer. 
Refrigerator <--AtLocation-- Milk <--RelatedTo--> Addition <--RelatedTo--> Cream 
Boat <--AtLocation-- Beer <--AtLocation-- Relief 