Used is related to Wood. Wood is a type of Material. Material is similar to Crucial. 
you are likely to find Cotton in/at/on South. South is related to Continent. Continent is related to Sea. Sea is related to Smell. 
Used <--RelatedTo--> Wood --IsA--> Material <--SimilarTo--> Crucial 
Cotton --AtLocation--> South <--RelatedTo--> Continent <--RelatedTo--> Sea <--RelatedTo--> Smell 