adj.警惕的;警觉的;戒备的;注意到;意识到
n.警报;警戒状态;警戒;警惕;戒备
vt.向…报警;使警惕;使警觉;使戒备;使认识到;使意识到
例句:
They were quiet during the alert.
警戒期间他们保持安静.
Don't alert the enemy.
不要惊动敌人.
Hearing this, I was instantly on the alert.
我一听这话, 当下就警惕起来.