信号响时，人人脱帽致敬。

Everyone uncovered when the signal sounded.

红灯常常是危险的信号。

A red lamp is often a danger signal.

没有视频信号。

There is no video signal.

灯塔每一分钟发出两次信号。

The lighthouse flashes singals twice a minute.

时钟信号输入端被设 计用于提供时钟信号。

A clock signal input is designed to supply a clock signal.

对随机信号和混沌信号的特性进行了分析比较。