Secondly, it is not advisable to take the attitude of betting on the topic when doing the postgraduate entrance examination. In fact, the update rate of "400 questions" is not so high, that is to say, not every year's "400 questions" are different from last year's brand-new questions, and it is very good to update 50%. But this is not to say that this book is not good. For some classic questions and questions that have not been tested, it is necessary to keep them. So don't be superstitious about counseling books, let alone the final simulation questions. Improving real strength is king.
Finally, talk about the necessity of doing 400 questions. First, in the sprint stage, we should do certain simulation questions, grasp the time of doing the questions, and check for leaks; Second, "400 Questions" has withstood the test of all candidates and has a good reputation. The key is that several sets of questions in the book are more regular. Although there are some difficulties, it is definitely not a very simple question to improve the confidence of candidates blindly because the questions are impartial and unfamiliar. Third, the difficulty of the "400 questions" is higher than the average difficulty of the real questions in previous postgraduate entrance examinations. You may not be so handy when practicing, but you should be fully prepared. No one knows whether this year's topic is simple or difficult, but the key point is: "400 questions" are used to grasp the time of doing the questions, check for missing parts and further sum up experience, not because of "400 questions".
To sum up, "400 questions" is not used for betting (candidates had better not be superstitious about betting books), but it is really important to use it in the sprint stage.
Good luck!