说明：  设计一台可供4名选手参加比赛的智力竞赛抢答器。 用数字显示抢答倒计时间，由"9"倒计到"0"时，无人抢答，蜂鸣器连续响1秒。选手抢答时，数码显示选手组号，同时蜂鸣器响1秒，倒计时停止。
(To design a game for four players to participate in the intellectual competition Responder. With Digital Display answer in his countdown, from " 9" countdown to " 0" when no one answer in his place, a continuous buzzer sound 1 second. Answer in his players, the digital display group number players, while buzzer sound 1 second, countdown stops.)