她有先见之明，经济上作了准备以防万一发生事故。

She had had the foresight to prepare herself financially in case of an accident.

《牛津词典》

我也给他买了一份人寿保险以防万一。

I have also taken out a life insurance policy on him just in case.

《柯林斯英汉双解大词典》

你很可能无需打电话，不过还是记下我的电话号码吧，以防万一。

You probably won't need to call—but take my number, just in case.

《牛津词典》

We handed out again the game with the numbers, but just in case, let me just read out the game you played.

再来介绍一下这个数字游戏,但是以防万一,我来介绍下游戏规则

耶鲁公开课 - 博弈论课程节选

So, there's been an active effort to reestablish the process of smallpox vaccination in case that's needed.

为了以防万一,现在正积极重建,能够制造天花疫苗的工艺进程

耶鲁公开课 - 生物医学工程探索课程节选

We got an easy one. Let's just for the heck of it I should have found some better examples before I tried this. No mutant spiders here.

我们有了个简单的数字,让我们以防万一,我应该在尝试这个之前找几个更好的例子。

麻省理工公开课 - 计算机科学及编程导论课程节选