Thick is related to Sauce. Sauce is a type of Season. Pepper is a type of Season. Pepper is related to Doctor. 
Used is related to Chair. Chair is the opposite of Stand. 
Thick <--RelatedTo--> Sauce --IsA--> Season <--IsA-- Pepper <--RelatedTo--> Doctor 
Used <--RelatedTo--> Chair <--Antonym--> Stand 