这一举动是给为他所害者的朋友们的一个信号，告诉他们他是个必须被小心对付的人。

This act was a signal to his victim's friends that he was someone to be reckoned with.

《柯林斯英汉双解大词典》

他找到了那盏蓝灯，给了她一个信号，让她把他拉上来。

He found the blue light, and made her a signal to draw him up again.

youdao

这个警报传递出一个信号给肾上腺使其释放出大量的应激激素，包括肾上腺素和皮质醇。

This alarm sends a signal to your adrenal glands to release a surge of stress hormones, including adrenaline and cortisol.

youdao

This densely tangled thicket of clustered consonants in this amazing couplet is a signal to us of the weight, of the import, of this terrible event.

这个密集杂乱的灌木丛,在这个对句中，弥尔顿给我们传递出一个信号，在这个可怕的事件中。

耶鲁公开课 - 弥尔顿课程节选

How do cells pass the signal from themselves to the next cell?

细胞怎样将信号传递给下一个细胞

耶鲁公开课 - 生物医学工程探索课程节选

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