设计一个四路抢答器。抢答器必须具有互锁功能，同时抢答时每次只能有一个输出有效。同时，抢答时具有计时功能，限定选手的答题时间，在接近规定时间时进行提示，达到规定时间发出终止音。主持人可控制加分或减分。-Answer to design a four-way device. Answer must have interlocking features, Answer at the same time when there can be only one output per effective. At the same time, with the time when the Answer function, the answer' s limited time in nearly prompted when a stipulated time to time issued by the provisions of the termination of the sound. Moderator points can be controlled or reduced hours.