the crux

剑桥词典

the most important or serious part of a matter , problem , or argument
关键；核心；症结
The crux of the country's economic problems is its foreign debt . 外债是该国经济问题的症结所在。
The issue of an arms embargo will be at the crux of the negotiations in Geneva. 武器禁运将是日内瓦谈判的核心议题。 返回 the crux