形容词警觉的,警惕的,注意的; 思维敏捷的; 活泼的
名词警报; 警戒状态
及物动词向…报警
形容词
1. The boy was alert in answering the stranger's questions.
男孩很机敏地回答了陌生人的问题。
2. You must keep alert in class.
你们应该在课堂上保持活跃。
及物动词
1. The doctor alerted me to the danger of a heart attack.
医生提醒我注意心脏病发作的危险。
2. alert的解释
2. She's alerted me for weekend duty.
她已通知我周末值班。
名词
1. She was always on the alert for some new calamities.
她总是保持警觉以防某种新的灾难。