Pre-alarm | Warning Preparation: Sound for 36 seconds, pause for 24 seconds, repeat 3 times (total 3 minutes) | Hint: Risk is approaching, prepare for shelter
Air Raid Alarm | Emergency Evacuation: Sound for 6 seconds, pause for 6 seconds, repeat 15 times (total 3 minutes) | Hint: Danger is imminent, immediately evacuate and take cover nearby
All Clear | Restore Order: Continuous long sound for 3 minutes | Hint: Danger is over, resume normal travel order
Generate air defense alarm promotional posters, aspect ratio 4:3, generate three different images, cartoon educational style
