It would have been strong 100 years ago, but now I probably wouldn't have picked it up at all if I hadn't deliberately tuned in to that wavelength to see if there was any signal left.

也许100年前会很强烈，而现在湮没在其他声音里了，我要抽丝剥茧的才能寻得半点蛛丝马迹。

youdao

At an agreed signal they left the room.

收到约定的信号后，他们离开了房间。

《牛津词典》

This in turn left its mark on the polarization of the next photon, so amplifying the signal.

光子就这样轮流地将它的偏振标记留给下一个光子，因而增强了信号。

youdao

A more intriguing possibility is that our genetic makeup includes a signal encoded by aliens in our DNA that might have been left hundreds of millions of years ago.

VOA: standard.2010.04.16

Wherever I went, I needed a constant handler and guide, and the spotty wireless signal often left me stranded the video window on my laptop in Texas frozen as the Robot Rachel in New York went dead.

WSJ: My Life as a Telecommuting Robot

The symbols at the left signal the directional change in net worth since last year.

FORBES: 200 Global Billionaires

It was an ironic victory, though, for the killer evidence supporting the Big Bang was also an extra-galactic radio signal one left over from the primordial fireball itself.

ECONOMIST: Obituary