A green light on a traffic signal means your car can continue on.

VOA: special.2010.05.23

The heater is on, it's producing heat until a negative signal is registered, 'oh we've gone too high', and then it turns off.

加热器会开着,一直产生热量直到它得到一个关闭的信号,噢我们弄得太热了,然后就关闭了

耶鲁公开课 - 生物医学工程探索课程节选

Most frequently, chord changes come on the downbeat so composers signal to us in a fourth way the downbeat by means of chord change.

通常,和弦的变化都在重拍上,所以作曲家们用这第四种途径,通过和弦的变化告诉我们重拍的位置

耶鲁公开课 - 聆听音乐课程节选

A signal from the TV tells each side of the glasses when to turn on and off, showing each eye slightly different images that create the sense of depth.

VOA: special.2010.01.26

If the temperature drops below a certain level it sends a signal, 'turn on the heat', and that signal stays on until it gets a negative signal to turn off.

如果温度降到一定程度以下时,探测器会发送一个信号,打开加热器,直到加热器再收到关闭的信号,它就会一直开着

耶鲁公开课 - 生物医学工程探索课程节选

"When we praise what the Palestinians do on security, it is meant to send a signal that progress is underway, and it is progress toward a two-state solution.

VOA: standard.2009.11.02

Now this is a rain gauge, and it's sitting on a roof of a building, and when the water falls into this gauge, it sends a signal to the logic unit of the computer, which immediately notifies the memory bank of the computer to seek out its instructions for a rainy day.

这是一个雨量测量器，安装在一个楼房的,屋顶上，当水流入到这个测量器，它就给计算机的逻辑部件发送一个信号，计算机立即通知内存条,为下雨天找出相应的指令。

哈佛公开课 - 计算机科学课程节选

The alleged use of special operations troops in the raid could signal a shift away from the controversial U.S.tactic of relying on long-range missile assaults to take out terrorist targets.

VOA: standard.2009.09.15

When you touch boiling water, for example,get a cut, or even exercise too much, a special receptor on the neuron is activated, sending a signal to the brain - that hurts!.

VOA: standard.2010.05.04

"She's not really trying to send any signal at all. This is a trip where we're trying to focus on India and really highlight the new strategic partnership, and again all the people-to-people ties.

VOA: standard.2009.07.15

Muhammad Salim Akhtar of the American Muslim Task Force on Civil Rights and Elections says Obama administration support for the opposition would send a signal that the United States favors full democracy in Pakistan.

VOA: standard.2009.03.11