exhort的名詞形式是什么

　　例句：

　　1、They had been exhorted to action.

　　已經(jīng)告誡他們采取行動。

　　2、The premier exhorted an economic reform.

　　總理呼吁實行經(jīng)濟改革。

　　3、The teacher exhorted him to work hard.

　　教師諄諄告誡他要用功。