它看起来很警觉。

It looks very ___alert.

地震发生后，整个城市都处于高度戒备状态。

After the earthquake, the whole city was on high ___alert.

警报系统会在台风临近时及时提醒居民。

The warning system will ___alert residents when a typhoon is approaching.

天气预报应用发出了暴雨警报。

The weather app sent an ___alert about the heavy rainstorm.