Sustain is a synonym of Aid. Aid is a synonym of Relieve. Relief is etymologically related to Relieve. 
Acquisition is related to Get. Get is related to Action. Action is related to Divide. 
Sustain <--Synonym--> Aid <--Synonym--> Relieve <--EtymologicallyRelatedTo-- Relief 
Acquisition <--RelatedTo--> Get <--RelatedTo--> Action <--RelatedTo--> Divide 