Variety is a synonym of Race. Race is a type of Compete. 
Sheet is related to Sail. Sail is related to Do. Add is etymologically related to Do. Add is a synonym of Supply. 
Variety <--Synonym--> Race --IsA--> Compete 
Sheet <--RelatedTo--> Sail <--RelatedTo--> Do <--EtymologicallyRelatedTo-- Add <--Synonym--> Supply 