Voice is the opposite of Fact. Fact is related to Item. Item is a type of Part. Part is a synonym of Participation. 
Adult is related to Sheep. Sheep is related to Parent. 
Voice <--Antonym--> Fact <--RelatedTo--> Item --IsA--> Part <--Synonym--> Participation 
Adult <--RelatedTo--> Sheep <--RelatedTo--> Parent 