費力不討好 [ㄈㄟˋ ㄌㄧˋ ㄅㄨˋ ㄊㄠˇ ㄏㄠˇ; fei4 li4 bu4 tao3 hao3] arduous and thankless task (idiom); strenuous and unrewarding ◄ ►