Knowledge is related to Brain. Brain is a synonym of Genius. Genius is a synonym of Mind. Mind is related to Control. 
Room is related to Fan. Fan is related to Crowd. Crowd is the opposite of Empty. Gut is a type of Empty. 
Knowledge <--RelatedTo--> Brain <--Synonym--> Genius <--Synonym--> Mind <--RelatedTo--> Control 
Room <--RelatedTo--> Fan <--RelatedTo--> Crowd <--Antonym--> Empty <--IsA-- Gut 