Sink is the opposite of Source. Source is related to Electricity. you are likely to find Electricity in/at/on Room. Surgery is a type of Room. 
Pepper entails/necessarily involves Throw. Basketball can be used for Throw. 
Sink <--Antonym--> Source <--RelatedTo--> Electricity --AtLocation--> Room <--IsA-- Surgery 
Pepper --Entails--> Throw <--UsedFor-- Basketball 