Ear is related to Song. Song is a type of Sound. Snap is a type of Sound. 
Poll is related to Roll. Roll is related to Small. Small is related to Cigarette. 
Ear <--RelatedTo--> Song --IsA--> Sound <--IsA-- Snap 
Poll <--RelatedTo--> Roll <--RelatedTo--> Small <--RelatedTo--> Cigarette 