Normal is a synonym of Conventional. Conventional is similar to Straight. Straight is the opposite of Bill. Bill is related to Excellent. 
Hard is related to Wood. Wood is related to Output. 
Normal <--Synonym--> Conventional <--SimilarTo--> Straight <--Antonym--> Bill <--RelatedTo--> Excellent 
Hard <--RelatedTo--> Wood <--RelatedTo--> Output 