Emergency is a synonym of Casualty. Casualty is a type of Victim. 
Drag is a type of Persuade. Sell is a type of Persuade. Sell is related to Trade. Traffic is a type of Trade. 
Emergency <--Synonym--> Casualty --IsA--> Victim 
Drag --IsA--> Persuade <--IsA-- Sell <--RelatedTo--> Trade <--IsA-- Traffic 