Pan is related to Butter. Butter is related to Roll. Roll is related to Trick. 
Hearing is related to Echo. Echo is related to Valley. you are likely to find River in/at/on Valley. 
Pan <--RelatedTo--> Butter <--RelatedTo--> Roll <--RelatedTo--> Trick 
Hearing <--RelatedTo--> Echo <--RelatedTo--> Valley <--AtLocation-- River 