-1. Choose the countdown time
-2. Click start to start the countdown
-3. Background sound effects can be turned on and off
-4. It is possible to quickly turn on and off the alarm clock after the countdown ends
-1. Choose the countdown time
-2. Click start to start the countdown
-3. Background sound effects can be turned on and off
-4. It is possible to quickly turn on and off the alarm clock after the countdown ends