Integrate is a synonym of Incorporate. Incorporate is a synonym of Comprise. Comprise is a synonym of Consist. Consist is a synonym of Formation. 
Complicated is the opposite of Plain. Plain is related to Basic. Basic is related to Unit. 
Integrate <--Synonym--> Incorporate <--Synonym--> Comprise <--Synonym--> Consist <--Synonym--> Formation 
Complicated <--Antonym--> Plain <--RelatedTo--> Basic <--RelatedTo--> Unit 