信号灯

• Mutual exclusion can be achieved with the use of a semaphore or mutex
  互斥现象能由使用信号灯或互斥完成。
• Colours and colour limits for signal lights ; railway signal lights
  信号灯颜色和颜色限制.第4部分:铁路信号灯
• Pneumatic stop light switches
  压缩空气制动信号灯开关
• The traffic lights tell us when to stop and when to go
  交通信号灯告诉我们什么时候该停下，什么时候可以走。
• Red fusee for motor vehicles
  机动车用红色闪光信号灯
• I wait for the light to change
  我等候信号灯变换。
• Auxiliary direction indicator lamps
  辅助转向信号灯
• Normally extinguished signal lamp
  正常熄灭的信号灯