一旦

一旦養成了壞習慣，就很難改回來了。

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

一旦撿到一顆你喜歡的石頭，盡快將它帶回家並好好對待它，因為那是妳唯一得到的石頭。

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.

一旦過了河, 你就安全了。

Once across the river, you are safe.

一旦爆發核戰爭，受苦的將會是全人類。

All humanity will suffer if a nuclear war breaks out.

这个进程一旦开始，我们能在一小时内得到结果。

這個進程一旦開始，我們能在一小時內得到結果。

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