埋头苦干的英语:work with quiet hard application; bury oneself in work; engage in unostentatious hard work; immerse oneself in hard work; keep one's nose to the grindstone; plug away; quietly immerse ones...
埋头苦干的法语:travailler dur(ou : d'arrache-pied,avec acharnement,avec application);s'acharner à son travail;faire des efforts assidus