I took some extra cash just to be on the safe side.

我多带了一些现金，以防万一。

You might still want to go for an X-ray, however, just to be on the safe side.

但你也许还想去拍张X光片，为保险起见。

"So you had better make it a round twenty years and be on the safe side," concluded the Clerk.

“所以你最好凑个整数，二十年吧，这样比较保险。”书记员总结道。

Just to be on the safe side.

站在安全的一边吧。

But you can't quantify exactly, so err on the safe side.

不过你没法子知道准确数量，所以这点小错在安全线以内。