我认为我不需要钱，但我会带一些以防万一。

I don't think I'll need any money but I'll bring some ___just ___in ___case.

带张地图以防你迷路。

Bring a map ___in ___case you get lost.

我带着手机以防万一。

I have my mobile with me ___just ___in ___case.