Apply is related to Attempt. Attempt is a synonym of Undertake. Undertake is a synonym of Contract. 
Skill is related to Writing. Writing is a synonym of Composition. Composition is a type of Essay. 
Apply <--RelatedTo--> Attempt <--Synonym--> Undertake <--Synonym--> Contract 
Skill <--RelatedTo--> Writing <--Synonym--> Composition --IsA--> Essay 