孜孜不辍

Explanation: Diligently engaged in efforts to specific, refused to stop. 　　Source: "East Han Ji Tang spreading the concept of" teacher was Liu Shu, often in the door division, commoner Acts, speaking chant diligently stopped working. " 　　Examples: Germany and the London re-word, something pro-filial piety, as officials honest, kind of school performance text, ~, see the book will pass, its possession of the house, often are all copied by hand from. ★ Song Bian, "Qu Wei River old news" VII