By dialing the right number, you may be able to select a play, golf lesson or lecture in physics, from a pretaped library in a remote city, for showing on your home screen.

• 只要拨对了号码，你就在家里电视机上选看到有远方城市一座图书馆发出的预先录制的一出戏、一堂打高尔夫球的讲课，一次物理学演讲。