you would Spit because Mad. Mad is related to Anger. Anger is related to Burst. 
Shoulder is a type of Joint. Shoulder is part of Road. Road is related to Flat. Flat is related to Land. 
Spit --MotivatedByGoal--> Mad <--RelatedTo--> Anger <--RelatedTo--> Burst 
Joint <--IsA-- Shoulder --PartOf--> Road <--RelatedTo--> Flat <--RelatedTo--> Land 