◎ 丁是丁，卯是卯 dīng shì dīng,mǎo shì mǎo

(1) [be conscientious and meticulous;be accurate in what one says;be fastidiously accurate] 丁、卯分别是天干、地支之一,不能相混,错乱了影响记时。形容做事认真,一丝不苟

凤姐笑道:“我看你厉害,明儿有了事,我也是丁是丁,卯是卯的,你也别抱怨。——《红楼梦》

(2) 也作“钉是钉,铆是铆”