I've seen him once or twice in town.

我在城里见过他一两次

I visited once or twice.

我参观过一两次。

He visits Paris once or twice a month.

他一个月去一两次巴黎。

We go there maybe once or twice a month.

我们每月大概去那里一到两次。

I don't know her well, I've only met her once or twice.

我跟她不很熟；我只见过她一两次。

Turn the shanks and baste them once or twice as they cook.

将小腿肉翻一下，烹调时在上面淋上一两次油。