alert

释义

a. 警觉的, 灵敏的, 留心的\nn. 警报\nvt. 使警觉, 通知, 使意识到 alert someone to sth 使...警觉；使...警惕 on the alert 提防；警戒著；随时准备著 red alert 紧急警报，红色警报；应急状况

例句

The school immediately alerted the police .

学校立即报了警。

The animal raised its head, suddenly alert.

那只动物突然警觉地抬起头来。