Doyouknowasayingabouttheswanfeather（天鵝羽毛）？ Thissayi...
問題詳情： Doyouknowasayingabouttheswanfeather（天鵝羽毛）？ ThissayingcomesfromahistoricbookcalledLuShi；Accordingtothestory，aTangDynastyofficial（唐朝官員）inYunnanwantedtoshowhisrespecttotheemperor．Hesenta...