Cover is related to Fabric. Fabric is related to Sail. Sail is related to Do. Do is a synonym of Achieve. 
United is related to Collective. Collective is related to Farm. Farm is related to Cow. you are likely to find Cow in/at/on Pen. 
Cover <--RelatedTo--> Fabric <--RelatedTo--> Sail <--RelatedTo--> Do <--Synonym--> Achieve 
United <--RelatedTo--> Collective <--RelatedTo--> Farm <--RelatedTo--> Cow --AtLocation--> Pen 