（1）用于竞赛强大的四人抢答器 （2）抢答开始后20秒倒计，倒计结束后无人抢答显示超时 （3）能显示抢答台号 （4）系统复位后进入抢答状态，能显示犯规警报-(1) is used to contest a powerful four Responder (2) to answer in 20 seconds after the start of countdown, countdown display time-out after no one to answer in (3) ca