The default value of b(t) is 0, which represents the normal state of the stadium, which includes the closure of the stadium and the ventilation of the stadium, and its value is 1 to kill the stadium
The default value of B (T) is 0, indicating the normal state of the venue. It includes the closure and ventilation of the venue. When its value is 1, the venue will be killed<br>
The default value of b(t) is 0, indicating the normal state of the venue, which includes the closure of the venue and the ventilation of the venue. When its value is 1, it will kill the venue.