1)　　设计一个八位竞赛抢答器：同时供8位选手或8个代表队比赛，分别用8个按钮S0-S7表示。
2)　　设置一个系统清除和抢答器控制开关S，开关由主持人控制。
3)　　抢答器具有锁存与显示功能，即选手按按钮，锁存相应的编号，抢答选手的编号一直保持到主持人清楚为止。(1) design an eight contest buzzer: 8 players or 8 teams, respectively, with 8 buttons, s0-s7.

2) set up a system cleaning and buzzer control switch S. The switch is controlled by the host.

3) there is a lock and display function of the answering device, that is, the player presses the button and the corresponding number is locked, and the number of the player is kept until the host is clear.)