Sofa can be used for Fucking. Fucking is a synonym of Bloody. Bloody is a type of Cover. Sheet is a type of Cover. 
Opera is related to Opportunity. Opportunity is related to Job. 
Sofa --UsedFor--> Fucking <--Synonym--> Bloody --IsA--> Cover <--IsA-- Sheet 
Opera <--RelatedTo--> Opportunity <--RelatedTo--> Job 