This is a letter to my son Xu Junhao who is the candidate for the college entrance examination this year. I love him and write some instructions to help him to overwhelm the course which is the key for him. Because the first step to entry university is the most important thing for him to choose the right key university. Later he will open new opportunity for his graduate course and career experience to famous reputation.so it is significant stage now to entry good key university. The reasonable instruction will help him to complete early entrying the high threshold to do more sophisticate skill and technology to promote his capability to high level which will wield effectiveness in his career experience later. The fitted method for him to conclude and grasp is most important thing to learn and acquire knowledge for high middle school subjects. The more exercising subject will be helpful to him more in order to promote the rank in class and grade. In order to entry the satisfied emphasis university he will dedicate himself to the final five months subject. To hope him to acquire good ranking in every simulated examination and college entrance examination hold in June 2023 in the end when he can entry the key university with his speciality smoothly.

Good jobs include university professors, research institute researchers and corporate researchers. The first two are iron rice bowls in state institutions, with fixed salaries and monthly pensions, which can basically guarantee a lifetime. University teachers have more than two months a year off, still pay, how well. Enterprises aim at making profits. It is good to keep employees and bad to fire them. There is no pension, which is very risky. I have to pay 1,400 yuan to the Social Security Bureau by myself, and I will only get a pension of about 2000 yuan after 15 years, which is very bad. I heard that now the institute has become an enterprise, which is responsible for its own profits and losses. So in order to a good career such as a university teacher must have a doctor's degree to enter. Master's students can only enter three, so it's best to aim for a PhD. Master's and master's degree in four years [1,2]. 

Good. Of course, graduates from national key universities such as 985 are the most impressive and can be admitted to one university. The quality and quantity of published papers are important indicators to evaluate which level of universities to enter. Writing a lot of papers is the key to becoming a famous scholar. SCI (science citation index) level 2 or above is the top grade paper, the highest level paper, the top grade paper. Son, this is for later, but you should keep it in your mind so that you can write it when you have a chance. I heard that some college students also write papers on mathematics, and the professor of Peking University asked him to study there for a master's degree after graduation, so that he could go to the United States for a doctorate and further development in the future. The United States also values scholars very much. All right, that's all we have time for. We'll talk later. I wish you study hard and make progress every day! If you have a doctor's degree from a key university in China, and have written more than ten papers, you can discuss entering a university. Of course, the more papers you write as the lead author, the better, because you are the lead author and competent, so they will be more willing to ask for them. If you have more than 50 papers after entering the university, you can apply for the academy of Sciences. The current salary of academicians is 15,000 yuan per month, and they can continue their research until their death after retirement. Academicians are the highest level of national scholar’s honour and treatment, the more papers, the better. One hundred ? two hundred or even three hundred is academician, that is, the greater contribution to the society, the better. All right, let's talk about this one. Let's see! If it is the foreign key university like Harvard, graduated from Yale University Dr., too, you can have foreign academician of academy of sciences of the title, where you choose to leave is your own problem. Do more exercises before the TOEFL test to adapt to the atmosphere of the test room, do 100 sets of questions to increase the ability to solve problems. Then make notes and lines in the places related to the topic to facilitate the problem combing, look at it again, save time, get a high score, get more than 90 points (120 points full). Listening, speaking, reading and writing are four aspects of the test, so we should pay attention to, highlight reading and writing. Ielts is also 7.0 out of 9.  If you learn mathematics well, you can become a mathematician, physics, chemistry or economist. A Chinese named Liu Lu became a mathematics professor at the age of 21. He only became interested in mathematics when he was in middle school, but he was not very interested in other subjects. In my junior year, I wrote a paper and was nominated as a professor by a professor at Peking University. Even a little bit of basic will do, more terrible than death is regret, must remember this sentence. The forefront of the era of courage, the strong learning. Practice intermediate and difficult questions, especially math questions. You don't want to lose marks on the mid-range questions, there are going to be two questions, lots of marks. Then there are two problems with large scores, we must contact these aspects of the problem, do know well, in order to successfully answer. Mathematics is the key battle, must pay attention to. 

8:18:29

According to a student who got 117 points in the college entrance examination in 1990, he loved to think about math problems and study math, which was the secret of his high score in math. Fear and avoidance are not good strategies. Be sure to remember!

8:18:29

How about modelling has it been made? If you want to learn chemistry, you can also do modelling, if possible, you can write a paper published. A PhD student in Tsinghua University has written more than one hundred papers in three years. How impressive! Contests in modelling for college and graduate students are very popular now, and they all use math as a tool. BP neural networks, deep learning machines and genetic algorithms are all built on the basis of mathematical models. Artificial intelligence (AI) is a software that is built using mathematics as a tool. You've learned robot hardware and software before. In the next volume of Advanced Mathematics there are least squares regression equations on the chemical formula, have a chance to look at

8:18:30

Dad wrote seven papers predicting the lottery using the least square method. Then the error is verified by standard deviation. The error is between 3 and 1. My son, it is very important to be admitted to the university and major you have in mind. From now on, you should strive to achieve your goals step by step and lay a good foundation for your future career. Also for the future graduate study, adapt to the social trend to lay a good foundation. There are a lot of things waiting for you to do so from now on more efforts to set goals to achieve it in order to do the future era of the tide, we believe you can do it, not to say more, some opportunities once lost will not come again, so cherish this half a year more time to do more questions, do more college entrance examination questions to make it, so that the examination room smoothly. Fight hard! Dad believes you can get into a good school! Dad book [OK] although there are thorns in front of you but persevere will reach the key university in your mind, dad believes you can do it! Your grandparents and your mother will help you when you need them. Be sure to believe in yourself! Have difficulty to communicate more, don't chuai heart, and tell us, we will help you! Goodbye 

7:57:37

Only by entering a key university can you have the chance to be admitted to a master's and doctoral program. It only takes 4 years to graduate. It's also in your interest to look at the bigger picture. Of course, your college record is the best evidence, the class ranked in the top 6 is very likely to be interviewed for employment. So from now on, try to get a good ranking, strive to enter the key university, is the road to success. Everything is difficult at the beginning, as long as you enter the key university, the ranking is not bad, and you will have the opportunity to enter the postgraduate. Getting a PhD from a good university is no problem. Work hard! On this road of hope. Of course, if you are lower than the sixth place in the university, you can choose to take the exam or go abroad to study, or get a PhD. You have to pass the language test first. If you get 85 TOEFL, you can go to a good foreign university for a PhD. From now on, you have to prepare for the TOEFL bit, which is the computer test. You get a PhD, you get an advantage, you get to stay and teach until you retire, and you get a pension. Of course you have to publish more than ten papers in reputable journals. If you're a full professor, you're tenured. There are also some honorary members of the Academy of Engineering, the president of the society, the editor-in-chief of the famous journal and so on with you throughout your life. Can also enter the institute as a researcher, it is not too fun, even have no holiday, but also have to write a paper. If you don't have a paper, you can only enter the enterprise, even less fun. That's all for today. I hope you can do well from the first step and work hard! Dad Book

7:57:37

Now you have reached the critical period must be prepared for the practice exam, stick to your ideal goal stride forward! Don't play games and study all the time. Don't look down on the test, see where you can go to college, all in this exam. Work harder! I believe you, son. Be sure to focus on ranking. Believe that you will reach the place in your heart. Don't be behind The Times, look down on the mock exam, it is the benchmark, whether you can succeed depends on whether you test good or bad. I remember that you are good at big exams and you did not do badly. Keep working hard, squeeze out hundreds of thousands of names in front of you, finish the BBK ranking, and finally achieve the set goal, Tongji University, Chemistry, chemical engineering or biology department. Success in excellence, begins with the first step! Dad believes in you. Grandpa and Grandma thank you too! Let me know if you're in trouble and we'll help you. You see, we've given you plenty of pocket money. You've got to get something in return, and that's good grades, you know? How diligent! Study hard! Improve your ranking! Class, grade, city and province. Well, let's just say that these dads keep their books at home.

7:57:39

Now the first prize is 3000 yuan, the second prize is 2000 yuan, and the third prize is 1000 yuan. There is also a national scholarship of 8,000 to 5,000 yuan, limited to the top one or two students in their major, can apply for it. You have to actively apply for Party membership to become an active member and get a national scholarship. Scholarships are awarded on the basis of comprehensive merit. The comprehensive score is calculated by the professional course score. If you are the first in your major, you can apply for the national scholarship, which is more money. Work hard! Son daddy believes you!!

7:57:40

Comprehensively improve the ability to solve problems, all types of questions to do, in case of failure to solve problems affect the exam confidence. And then we'll focus on what went wrong? How do I prevent this from happening again? Solve the problem must be smooth, otherwise will be confused thinking, I do not know the action. So to a set of college entrance examination questions in the exam time to finish, see the test score? If you reach an excellent level or not, think more about what's going on and what's going wrong and why. Write down the reasons for the mistakes, and read more in the future, so that you will not make the same mistake again. Take a look at the types of questions you love to solve and the types of questions you don't love to solve, keep the advantages of the former and dig out the questions you don't like to solve. Be balanced and not biased. Try to improve the overall ability to solve problems, will be maintained and difficult, not too familiar to increase the strength to cook it, turn him over. Only by comprehensively improving problem solving ability can we achieve excellent overall results and improve competitiveness. Dad Book

7:57:40

Find out your study pattern, which time to learn what courses are efficient? Arrange your time wisely to learn what? How long? Know your body clock. This will increase productivity, memory and comprehension. Get more done with less. Learn more about yourself. If you don't understand well at a given time, move on to another course. You also need to know what courses you are interested in, do more exercises, and understand to a certain depth, to integrate, you can write a paper. Do not blindly write to have a certain depth, to be practical in writing. Make you have fun in the efficient problem solving, will increase the efficiency of the problem. To do more difficult exercises, by analogy, drive the ability to solve middle - and upper-class exercises. Because the former is a pull problem and the latter is a better understanding of the problem, it is difficult to open the grade. Especially now is a more critical period, practice the last two questions of the college entrance examination and the types of questions you think have problems, to achieve who can make perfect, easy to pull. All right, Dad, that's all

7:57:40

By constantly doing exercises, improve the speed of problem solving, comprehensively understand the types of questions in the college entrance examination, and improve the score and ranking. Strive to further improve the speed of problem solving, and ensure no mistakes. In this way from passive to active, strive for good grades. The only way to improve speed is to solve a lot of questions, especially the gaokao questions. Correct analysis of the essence of the college entrance examination questions, in order to understand the truth, so that you correctly analyse your weaknesses, and to overcome, to ensure that the solution of a problem to a problem, of course, you should quickly solve the problem, because you cannot delay too much time on a problem, so as not to affect the quality of the future problem. So you have to be prepared, you have to cook it, you don't have to regret going too slow. Ask more questions of students who are better than you, check the gap, supplement it carefully, and surpass him. Dad Book

7:57:40

College entrance examination questions pay attention to the transformation of formula and simplified application, pay attention to analysis. How to transform and simplify is the key. Pay attention to the analysis of how to derive the process to understand the details, thinking many times to remember. Only by finding out the key steps to study, understanding and remembering them, can we find out the problem solving method, recall and remember the process of one or two, three or more. Only by sticking to it, can we thoroughly understand the process of problem solving by memory, get interested in learning about it, get high marks, improve the ranking, enter a satisfactory university or even pursue a PhD to find a job, live a satisfactory life and love life. Successful career, happy family, old age.

Now the first prize is 3000 yuan, the second prize is 2000 yuan, and the third prize is 1000 yuan. There is also a national scholarship of 8,000 to 5,000 yuan, limited to the top one or two students in their major, can apply for it. You have to actively apply for Party membership to become an active member and get a national scholarship. Scholarships are awarded on the basis of comprehensive merit. The comprehensive score is calculated by the professional course score. If you are the first in your major, you can apply for the national scholarship, which is more money. Work hard! Son daddy believes you!!

1. Compilation group of economics textbook series. Microeconomics [M]. Eco Sci press. 2013.
2. Run Xu. Modelling of economic cost distribution in thread process of screw. J Eco Sci Res. 2020; 03: 23-24.