Factory is related to Huge. Huge is related to Crowd. Crowd is a synonym of Gang. 
Grade is a synonym of Form. Form is related to Dance. Dance is related to Musical. 
Factory <--RelatedTo--> Huge <--RelatedTo--> Crowd <--Synonym--> Gang 
Grade <--Synonym--> Form <--RelatedTo--> Dance <--RelatedTo--> Musical 