Excuse is a type of Explanation. Explanation is related to Explain. Explain is a synonym of Couch. Couch is related to Furniture. 
Pack is a synonym of Box. Bush is etymologically related to Box. Bush is related to War. you are likely to find Pain in/at/on War. 
Excuse --IsA--> Explanation <--RelatedTo--> Explain <--Synonym--> Couch <--RelatedTo--> Furniture 
Pack <--Synonym--> Box <--EtymologicallyRelatedTo-- Bush <--RelatedTo--> War <--AtLocation-- Pain 