Pesquise pelo NPC Jamo Hasa .. Ron esta na frente dele
http://prntscr.com/uhamb2
http://prntscr.com/uhan71

The game changed the knowledge to workers green worker in the lake area. One of the two green workers

For English, it's Jamo Hasa South of Ancient Ruins Excavation Site. There you will see Ron near him (and other NPCs for knowledge as well: Bully and Totenan!). Do them all!