然而，拿武器做文章是波尔顿这位防核扩散老手的拿手好戏。

But on weapons, Mr Bolton, an old counter-proliferation hand, is in his element.

根据学校的规定，在这一天，大家可以任意在自己的发型和颜色上做文章，看一看谁的头发最别出心裁。

The only rule was whatever you did to your hair, had to be done in a way that you could fix by the next day.