- unit-32 -> unit-3d
- unit-3d -> unit-4
- unit-4 -> unit-4
- unit-4 -> unit-4-africa
- unit-4-agents-of -> unit-4-beware-of
- unit-4-beyond-vi -> unit-4-civil-war
- unit-4-civil-war -> unit-4-determina
- unit-4-developme -> unit-4-exam
- unit-4-exam-ques -> unit-4-global-wa
- unit-4-globaliza -> unit-4-imperiali
- unit-4-imperiali -> unit-4-lesson-19
- unit-4-lesson-2 -> unit-4-money-ban
- unit-4-money-ban -> unit-4-note-taki