Tank is related to Storage. Trunk can be used for Storage. Automobile have Trunk. Auto is etymologically related to Automobile. 
Perfect is a synonym of Pure. Pure is a synonym of Innocent. 
Tank <--RelatedTo--> Storage <--UsedFor-- Trunk <--HasA-- Automobile <--EtymologicallyRelatedTo-- Auto 
Perfect <--Synonym--> Pure <--Synonym--> Innocent 