Occupy is a synonym of Concern. Burden is a type of Concern. Burden is a type of Idea. 
Kind is related to Very. Very is related to Cold. Cold is related to Whale. 
Occupy <--Synonym--> Concern <--IsA-- Burden --IsA--> Idea 
Kind <--RelatedTo--> Very <--RelatedTo--> Cold <--RelatedTo--> Whale 