Once time has gone by, it will never return.

时间一旦消逝，就永不再回来了。

youdao

On turning 30: "I kind of feel like the same person except more time has gone by."

关于年届三十：“我觉得我没什么变化，只不过更多的时光流逝了。”

youdao

Time is precious. Nobody can afford to waste time. Once time has gone by, it will never return.

时间是宝贵的，没有人能浪费得起时间，一旦时间流逝后，再也不会回来了。

youdao

Ironically, the one area where the passage of time can help cooperating witnesses has gone unrecognized by most reported authorities.

FORBES: The Ghosts of Prosecutions Past: Cooperating Defendants and the Ravages of Time

But the fact is that the world is changing so fast that the reality we are dealing with - mass migration, organised crime, ASB - has engulfed systems designed for a time gone by.

BBC: NEWS | UK | UK Politics | In full: Tony Blair's speech

She says the difficulty with evidence is that children will not disclose what has happened to them until they have been taken away from the perpetrators for several months, by which time, the evidence has gone cold.

BBC: Police investigate satanic abuse charges