Then, just by chance, he walked into a Western medicine shop and, his mind empty, looked distractedly at the Western medicine of various kinds.

他鬼使神差地走进了一家西药房，怔怔地望着各式西药，脑中一片空白。

youdao

I didn't think you'd be at home but I just called by on the off chance.

我想你不会在家，只是碰碰运气顺路来看一下。

《牛津词典》

I came here by chance and was just watching what was going on, when this girl came up to me.

我碰巧来到这里，正在看热闹，这时一个女孩向我走来。

《柯林斯英汉双解大词典》

The American College of Obstetricians and Gynecologists said the timing was just by chance.

VOA: special.2009.11.25

One nice thing, by the way -- this is just chance I think -- the median answer in the class was nine, which is spot on, so the median hit this bang on.

顺便提一下,有趣的是,我就是顺便提一嘴,班级中位数也是9,中位数正好也是游戏的答案

耶鲁公开课 - 博弈论课程节选

It was just by chance that I had that one little piece of information.

NEWYORKER: Free Radicals

If every potential outcome were measured, something would always come up positive just by chance.

FORBES: Is Provenge The Most Important Medicine In Biotech?

If you do enough tests, one will be high just by chance-- causing unnecessary anxiety and yet more tests.

FORBES: Magazine Article