Household is related to Servant. Servant is related to Nice. Nice is related to Dress. 
Lens is a type of Organ. Lens is related to Device. Device is related to Bomb. 
Household <--RelatedTo--> Servant <--RelatedTo--> Nice <--RelatedTo--> Dress 
Organ <--IsA-- Lens <--RelatedTo--> Device <--RelatedTo--> Bomb 