At the first sign of trouble, the crowd melted away.

人群一看有麻烦，便渐渐散了。

《牛津词典》

We can't just walk away from it at the first sign of a problem.

我们不能一遇到问题就逃避。

youdao

At the first sign of trouble, schooling fish swim as close together as they can get.

一旦发现危险的迹象，鱼群就会尽可能地游近彼此。

youdao

The first sign of trouble was a tiny burst of light in the western sky over the United States.

VOA: special.2009.07.22

In the first passage, the statement about language by criticism, that sign and meaning can never coincide, is what is precisely taken for granted in the kind of language we call "literary."

在第一段，关于语言的主张，用批判的方式，认为符号和意思永远不能相矛盾，正是这个主张,被人们认为是理所当然的，对于我们所说的文学语言来说“

耶鲁公开课 - 文学理论导论课程节选

The very first thing I know is that it's a sign that says "exit."

我最先知道的是这是一个标志，上面写着存在“

耶鲁公开课 - 文学理论导论课程节选

At the first sign of a strengthening dollar, you should sell the bond, she says.

FORBES: The Global Test

Those businesses will have capital to reinvest at the first sign of market recovery.

FORBES: Top 10 Industries: Growing Margins in Growing Uncertainty

And don't ask for a raise at the first sign of your company's turnaround.

WSJ: It Can Be Done: Landing a Raise In a Recession