Glad is related to Feeling. Feeling is related to Care. 
Busy is related to Action. Action is related to Remain. Remain is a synonym of Persist. Persist is a synonym of Prevail. 
Glad <--RelatedTo--> Feeling <--RelatedTo--> Care 
Busy <--RelatedTo--> Action <--RelatedTo--> Remain <--Synonym--> Persist <--Synonym--> Prevail 