Letter is a type of Earn. Letter is related to Message. Request is a type of Message. 
Degree is related to Division. Division is related to Divide. Divide is the opposite of Unite. 
Earn <--IsA-- Letter <--RelatedTo--> Message <--IsA-- Request 
Degree <--RelatedTo--> Division <--RelatedTo--> Divide <--Antonym--> Unite 