Income is a synonym of Yield. Yield is a synonym of Afford. Afford is related to Money. Money is related to Guard. 
Event is related to Born. Born is related to Begin. Begin is a different concept from Middle. Middle is related to Road. 
Income <--Synonym--> Yield <--Synonym--> Afford <--RelatedTo--> Money <--RelatedTo--> Guard 
Event <--RelatedTo--> Born <--RelatedTo--> Begin <--DistinctFrom--> Middle <--RelatedTo--> Road 