alerted

n.

condition of heightened watchfulness or preparation for action

"bombers were put on alert during the crisis"

同义词：qui vive

a warning serves to make you more alert to danger

同义词：alerting

an automatic signal (usually a sound) warning of danger

同义词：alarmwarning signalalarum

1. The authorities alerted the public about the severe weather conditions expected this weekend.
   当局已警告公众本周末将有严重的天气状况。
2. She alerted her colleagues to the changes in the schedule as soon as she found out.
   她一发现日程有变动，就立即提醒了同事们。