事非经过不知难的英语:not to know how difficult the job is, unless one has done it oneself; a man does not know the difficulty of anything unless he does it personally.; one cannot appreciate the difficulty exc...
事非经过不知难的俄语:pinyin:shìfēijīngguòbùzhīnán пока дело не сделано, не узнаешь его трудности