This is necessary. Teacher Li Yongle's cold-blooded and simulated test paper sets must be done later, and be familiar with the test rhythm. There are both test papers and question classification, one brush test paper, two or three brush test questions, and the analysis is clear and complete. A problem often has many solutions, and it is a very comprehensive test set, so it is necessary to buy it. Cold War is a book published by Xi Jiaotong University Press, and the authors are Li Yongle, Wang Shian and Wu Zhongxiang. It's a review book for postgraduate entrance examination.