主控开关先复位，然后再断开，选手开始抢答，译码显示出来，同时，选手答题的计时开始，到计时为0后，报警电路有效，开始报警。然后主控开关进行复位，准备下一轮的的抢答。用multisim进行仿真。-Master switch to reset, and then disconnect, players start Answer, decoding displayed at the same time, players begin to answer in time to time to 0, the