Original is a synonym of Master. Master is related to Lock. Lock is related to Protection. City can be used for Protection. 
Exchange is related to Mail. Mail is related to Package. Form is part of Package. Form is related to Fill. 
Original <--Synonym--> Master <--RelatedTo--> Lock <--RelatedTo--> Protection <--UsedFor-- City 
Exchange <--RelatedTo--> Mail <--RelatedTo--> Package <--PartOf-- Form <--RelatedTo--> Fill 