摘要：一个好的文章要有好的开始，引言部分应尽量简洁，但能吸引读者的注意

Abstract: <br>A good article must have a good start. The introduction should be as concise as possible, but it can attract the attention of readers. To make our ideas more scientific and explain the reality, we need abstract thinking to build a model. A model is to connect the variables involved in the problem together and explain the relationship between two or even several variables. The variables here involve Endogenous variables and exogenous variables must be distinguished. A good model should be designed with harsh assumptions at the beginning, that is, the model should be as simple as possible, until only the necessary components of the model are included. This model may be a special case of some other models, and may only illustrate the simplest and obvious The problem, this is a time-consuming task, hold on. Later, we expanded it and added some constraints and variables to generalize it. In this process, we must consider possible problems and know the problems that it can explain and the problems that cannot be explained. We will make many mistakes in the modeling process, but this is necessary. One mistake will be lost until our model can justify itself, that is, the deduced conclusion is consistent with reality. If it does not match, we must first look at our model. Whether the establishment and analysis are correct, or modify your own ideas.

Summary:<br>A good article should get off to a good start, and the introduction should be as concise as possible, but it can attract the reader's attention. To make our ideas more scientific and practical, we need abstract thinking to build models that link the variables involved in the problem and illustrate the relationship between two or even several variables, where the variables involved are endo-variables and exo-variables, which must be distinguished. A good model should start with the harsh assumption that the model should be as simplified as possible until it includes only the necessary components of the model, which may be a special case for some other model, perhaps only to illustrate the simplest and most obvious problem, which is time-consuming work and persists. Later we expanded it to include constraints and variables to generalize it, taking into account possible problems, knowing the problems it could explain and the problems that could not be explained. We make a lot of mistakes in the modeling process, but this is necessary, turning over a mistake will be less than one, until their own model can be self-narcissism, that is, to derive the conclusion is consistent with reality, if not the first thing to see their own model is established and analyzed correctly, or modify their own ideas.

Abstract:<br>A good article should have a good beginning. The introduction should be concise, but it can attract the attention of readers. In order to make our ideas more scientific and more able to explain the reality, we need to build a model of abstract thinking. A model is to connect the variables involved in the problem together and explain the relationship between two or even several variables. The variables here involve endogenous variables and exogenous variables, which must be distinguished. A good model should be designed with strict assumptions at the beginning, that is, the model should be simplified as far as possible until only the necessary components of the model are included. This model may be a special case of some other models, and perhaps it can only explain the simplest and obvious problems. This is a time-consuming work. Stick to it. Later, we expanded it by adding some constraints and variables to generalize it. In this process, we should consider the possible problems and know the problems that can be explained and the problems that can not be explained. In the process of modeling, we will make a lot of mistakes, but this is necessary. If we turn over one error, we will lose one until our own model can justify itself, that is, the conclusion derived is consistent with the reality. If not, we should first see whether the establishment and analysis of our own model are correct, or modify our own ideas.<br>