Daily Chinese Idiom Guessing Game
To be perfectly clear or obvious; crystal clear.
十分清楚、明白。
老舍《四世同堂》小顺儿样样事情都要闹个一清二楚，不然怎么能当好妈妈的保镖呢。”
After his explanation, the whole situation was yī qīng èr chǔ.