alert

警觉的、机警的、留意的

Drivers must stay alert on long stretches of highway.

驾驶人在长途高速公路上必须保持警觉。

反应灵敏的、机灵的

Despite her age, she remains mentally alert and curious.

尽管年纪大了，她思绪依然灵敏、充满好奇心。

意识到的、警惕的常接 to

Parents should be alert to sudden changes in behavior.

家长应留意孩子行为上的突然转变。

警报、警示

The city issued a flood alert late last night.

市政府昨天深夜发布了洪水警报。

警戒状态、戒备常用于 on alert

Security teams were put on high alert during the summit.

高峰会期间，维安团队进入高度戒备状态。

提示、通知

I set up an alert for any price drop on that laptop.

我设了通知，那台笔电一降价就会提醒我。

向…示警、通报

A neighbor alerted the police to the smell of gas.

一位邻居向警方通报有瓦斯味。

使警觉、提醒

The report alerted the public to the risks of the new drug.

这份报告让民众警觉到这款新药的风险。