Ko e ha ʻoku tunnels fakaʻaongaʻi ai ʻa e ngaahi maama ʻo e tohi fakamoʻoni

Lolotonga ʻo e ngaahi kasa velangofua, hange ko e methane, ʻOku faʻa hoko ʻi he tunnels. ʻOku fie maʻu ke fakaʻaongaʻi ʻe he ngaahi tuʻutuʻuni ki hono tokangaʻi ʻo e maluʻi ʻa e mama hono naunau.