短语 “at a snail's pace（以蜗牛的速度）” 的意思是 “像蜗牛爬行一样，速度非常慢”。

例句

The traffic is moving at a snail's pace so we're going to be late.

交通速度慢得像蜗牛一样，所以我们要迟到了。

I'm so tired. I'm only working at a snail's pace today.

我太累了。我今天工作的速度慢极了。

The building work is only progressing at a snail's pace.

建筑工程进展非常缓慢。