Bridge is part of Guitar. Bridge is related to Gate. Gate is related to Metal. Car is made of Metal. 
Shell is a type of Housing. Housing is related to Farm. Farm is related to Land. Land is a synonym of Domain. 
Guitar <--PartOf-- Bridge <--RelatedTo--> Gate <--RelatedTo--> Metal <--MadeOf-- Car 
Shell --IsA--> Housing <--RelatedTo--> Farm <--RelatedTo--> Land <--Synonym--> Domain 