His vocabulary improved quickly in the beginning but then plateaued as he became busier and busier.

他的词汇量在开始时迅速提高，但后来随着他越来越忙，他的词汇量就停止不前了。

Unemployment has at last plateaued out.

失业情况终于稳定了下来。

Homicide rates in those areas have recently plateaued.

在这些地区的杀人率最近达到平衡。

Out-of-wedlock birth rates have plateaued for blacks.

他们不知道这孩子是不是婚生的。

David: Hmm. So, basically, even if sales have plateaued, the ginseng teas are doing well.

大卫：嗯。那么说，即使销售额不变的话，人参茶基本上也是有不错的表现的。

We all go through times where we feel like we've plateaued or when our passion wanes a bit.

我们都会有时觉得已经到了顶点或者热情有些消退了。