responsible的名詞是responsibility.
釋義：n. 責(zé)任，職責(zé)；義務(wù)
固定搭配：take responsibility 承擔(dān)責(zé)任；responsibility system 責(zé)任制
例句：They frankly admitted their responsibility.
他們坦率地承認(rèn)了責(zé)任。