Analysis of the test questions: "Sometimes learning the historical lessons of predecessors will lead to new problems", BCD is a correct summary of the lessons of the demise of the previous dynasty, and A reflects that Korea mistakenly learned the lessons of Qin's death and promoted the parallel system of counties and countries, which led to the emergence of kingdom problems. So choose a.

Comments: Kao paid special attention to the propositional examination of local jurisdiction measures by the ancient central government, highlighting the examination of the county system, the parallel system of counties and countries, the civil service system and the provincial system. (2) From the propositional point of view, it mainly investigates the understanding of the connotation, characteristics and influence of the three systems through the setting of new situations and new materials, and also investigates the understanding of the evolution law of ancient local systems. (3) The college entrance examination may strengthen the examination of the particularity of local administrative system and the proposition of local supervision system. When reviewing and preparing for the exam, we should pay attention to combing the evolution and laws of the local management mode of the ancient central government, and understand the important role of the local management system in the development and consolidation of multi-ethnic countries at that time and its far-reaching influence on future generations.