A cardinal rule or quality is the one that is considered to be the most important.
chief , principal
As a salesman, your cardinal rule is to do everything you can to satisfy a customer.
作为一名推销员,首要原则就是要尽你所能使客户满意。
cardinals
A cardinal is a high-ranking priest in the Catholic church.
In 1448, Nicholas was appointed a cardinal.
1448年,尼古拉斯被任命为红衣主教。