Inform is a type of Communicate. Sound can be used for Communicate. Sound is related to City. 
Bath can be used for Relax. Bath is related to Body. Body is related to Class. 
Inform --IsA--> Communicate <--UsedFor-- Sound <--RelatedTo--> City 
Relax <--UsedFor-- Bath <--RelatedTo--> Body <--RelatedTo--> Class 