While at university, he also undertook production training at Pyongyang Textile Machinery Factory, as a road-working apprentice and as a worker building TV broadcasting equipment. 大学期间他作为学徒工和生产电视广播设备的工人在平壤纺织机械厂参加生产训练。
Stress on practise training, learning doing in the doing through apprentice follow master worker; 注重实践训练,以师傅带徒弟的形式在做中学会做;