Reaction is related to Nuclear. Nuclear is related to Sun. Sun is related to Hat. 
Direct is a synonym of Aim. Aim is a synonym of Propose. Propose is related to Marry. Married is a form of Marry. 
Reaction <--RelatedTo--> Nuclear <--RelatedTo--> Sun <--RelatedTo--> Hat 
Direct <--Synonym--> Aim <--Synonym--> Propose <--RelatedTo--> Marry <--FormOf-- Married 