in case (sth happens) · if · once (sth happens, then...) · when · in a short time · in one day

A bad habit, once formed, is difficult to get rid of.

China is a sleeping tiger, but once it wakes up, it will shock the world.

Once across the river, you are safe.

Once you've picked up a stone that you like, take it home as soon as you can and treat it well, because that's the only stone you've got.

Once this process is started, we can get the result within one hour.