<prompt> Ngwala go tšwela pele bakeng sa serapa se - O thopile sefoka sa gauta go acroski ballet ya go thelela lehlweng go FIS Freestyle World Ski Championships ka 1986  <response>: kua Tignes. Kua FIS Freestyle World Ski Championships ka 1989 kua Oberjoch, o thopile sefoka sa bobedi sa gauta ka go ski ballet. O thopile sefoka sa silifera ka go ski ballet ka FIS Freestyle World Ski Championships 1991 ka Lake Placid. 