Because simultaneous interpretation requires intense concentration, every 30 minutes, the pair switches roles.

由于同步口译得聚精会神、燃烧脑力，每30分钟便会与搭挡对换角色。

But after the advent of radio technology, a new simultaneous interpretations system was developed in the wake of World War II.

但随著无线电的发明，在二次世界大战时发展出了「同步口译」的系统。