Tonga - variety of oddball plates

 WHO

World Health Organization

 CCECC:

China Civil Engineering Construction Corporation
possibly a personalized plate

PRB

Listed by Europlate as standing for Population Reference Bureau.  This is almost certainly not true.  They seem to be some type of bus pate.

Personalized, "FRIENDS"

 AFC

Personalized plates on two busses from ‘Apifo’ou College.