基本解释徒勞無功;枉費心機英汉例句雙語例句It is useless to flog a dead horse.鞭打死馬,徒勞無益。dict.cnIt is useless to flog a dead horse.鞭死馬無益;勿舊調重彈。edu.sina.com.cnto flog a dead horse更多例句