Divide is the opposite of Multiple. Multiple is related to Reaction. Reaction is related to Shock. Shock is related to Harsh. 
Hurricane is related to Event. Exercise is a type of Event. Swimming can be used for Exercise. Swimming is related to Plunge. 
Divide <--Antonym--> Multiple <--RelatedTo--> Reaction <--RelatedTo--> Shock <--RelatedTo--> Harsh 
Hurricane <--RelatedTo--> Event <--IsA-- Exercise <--UsedFor-- Swimming <--RelatedTo--> Plunge 