Smart is the opposite of Simple. Simple is related to Ordinary. 
Distinguish is related to Make. Make is related to Tree. Ash is a type of Tree. Ash is related to Dust. 
Smart <--Antonym--> Simple <--RelatedTo--> Ordinary 
Distinguish <--RelatedTo--> Make <--RelatedTo--> Tree <--IsA-- Ash <--RelatedTo--> Dust 