This time the display flashed a red warning signal.

【display】这次显示器上闪烁着红色的报警信号。

If these indicator bacteria are able to grow when they are added to the droplet, then we get a light signal—a green or red signal of this droplet.

如果这些指示细菌在被添加到液滴中时能够生长，那么我们就会得到一个光信号——这个液滴的绿色或红色信号。

A gang of 15 men from across London's underworld stopped a train by turning the signal red, brutally coshed the driver and made off with ￡2.6m (then $7.3m) in cash from the mail cars.

十五名伦敦黑帮组成的犯罪团伙通过将信号灯变成红色让火车停下来，随后暴打司机并带着260万英镑（约合730万美元）逃离邮车。