caution的形容词形式怎么写

　　例句：

　　Caution! This truck is reversing.

　　小心！卡车在倒车。

　　'Caution' is the key word in this situation.

　　在此情形之下，caution为关键词。

　　I would caution against getting too involved.

　　我要提出警告，别介入得太深。