A: Two, one to do it and one to assert that the bulb didn't exist before it was lit up.
A: Two, one to do it and one to assert that the bulb didn't exist before it was lit up.
回答：2位。一位去安装；另一位去声明：亮灯之前，灯泡并未存在。
A: Two, one to do it and one to assert that the bulb didn't exist before it was lit up.
回答：2位。一位去安装；另一位去声明：亮灯之前，灯泡并未存在。