Improved is a form of Improve. Approve is etymologically related to Improve. Approve is a synonym of Okay. 
you are likely to find Clock in/at/on Wall. Clock is related to Nice. 
Improved --FormOf--> Improve <--EtymologicallyRelatedTo-- Approve <--Synonym--> Okay 
Wall <--AtLocation-- Clock <--RelatedTo--> Nice 