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
It's from the Fathers and Sons' Breakfast
那是在父子早餐会上拍的。
Care brings grey hair.
忧虑催人老。
He built a glass wall through which he could watch what went on inside.