Extra is a synonym of Additional. Additional is related to Amendment. Amendment is related to Changing. Changing is related to Move. 
you are likely to find Jewelry in/at/on Box. Medal is a type of Jewelry. Medal is related to Olympic. 
Extra <--Synonym--> Additional <--RelatedTo--> Amendment <--RelatedTo--> Changing <--RelatedTo--> Move 
Box <--AtLocation-- Jewelry <--IsA-- Medal <--RelatedTo--> Olympic 