nub
n[sing]
the ~ of sth central or essential point of a problem, matter, etc (问题、 事情等的)中心,要点
The nub of the problem is our poor export performance. 问题的关键是我们出口贸易方面太差.
🗣️ 情景例句
Not now, I'm not in the mood for an argument.
别这样,我可不想吵架。
It's a dark town.
这是一个黑暗的乡镇。
It was raining heavily and they found that a stream had formed in the field.