Soap is related to Powder. Flour is a type of Powder. 
Common is related to Cotton. Cotton is related to Natural. Natural is related to Rain. Rain is related to Flood. 
Soap <--RelatedTo--> Powder <--IsA-- Flour 
Common <--RelatedTo--> Cotton <--RelatedTo--> Natural <--RelatedTo--> Rain <--RelatedTo--> Flood 