His anxiety about the work was just a passing phase.

他对工作的担心只是暂时的。

《牛津词典》

The teenage conflicts that erupt in most healthy families should not be taken lightly or ignored as a passing phase.

即使是发生在最健康家庭中的青少年问题，我们也不应该放松警惕，不该将其视作一种正常的过渡阶段而忽略它。

youdao

You must know, everything is a passing phase. Everything will come to an end soon, because there is nothing permanent.

每件事来的快去的也快，因为没有什么是永恒的。

youdao

And Mr Bush had previously said deficits would be merely a passing phase, a claim that looks increasingly dubious.

ECONOMIST: The state-of-the-union address

Recent governmental and intergovernmental activity in these areas is not a passing phase.

FORBES: Why The Next Apple, FedEx Or McDonald's Won't Come Out Of Europe

We now know that oak seedlings rarely thrive under mature oaks (which rain caterpillars on them), so the oak climax was just a passing phase.

WSJ: Ecology and Change: Nature Has No 'Balance' for Us to Keep | Mind & Matter