习焉不察

Explanation: Study habits; Yan tone words, there is this "means; aware of the police. Refers to the frequent contact with some things, but not aware that the existing problems. 　　Usage: Partial official; as the predicate attribute; containing derogatory 　　Source: "Mencius on the" line of rather than the Yan, Yan Xi carry on without the police, for life without knowing from which Tao, the public also. " Thesaurus:  Learning rather than the police