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

He said they would rise up at the first sign of a leader who wished to break their chains.

VOA: special.2009.06.18

So, what I want to do is, I want to discuss the scientific notion of language, at first restricting myself to systems like English and Dutch and American sign language and Navajo and so on.

因此,我想做的是,我想来谈谈语言的科学定义,首先我会将自己限定在,诸如英语,荷兰语,美国手语,或迪瓦霍语等语言系统之下

耶鲁公开课 - 心理学导论课程节选

In April,after the first cases in the United States, officials told schools to close at the first sign of an H1N1 outbreak.

VOA: special.2009.08.05

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