逻辑开关K0～K7代表竞赛抢答按钮0～7号，当某个逻辑电平开关置“１”时，相当某组抢答按钮按下。在七段数码管上将其组号（0～7）显示出来。-Logic Switch K0 ~ K7 on behalf of race to answer in the button 0 ~ 7, when a logic level switch set to " 1" when the button is pressed to answer in quite a group. In the s