The introduction part explains the causes of the selection of the subject, describes the present academic research on price discrimination and presents the research methods of this thesis.
引言部分主要介绍本文的选题缘由、学术界对价格歧视研究的现状，以及本文研究所遵循的思路。
2
The adverse selection of population quality of China is not only the research object of many subject, but also is arguing focus of academe.
中国的人口素质逆淘汰问题不仅是多学科的研究对象，而且是学术界争论的焦点。
3
The subjectselection, scheme preparation, theoretical analysis, experiment and development, appraisal of achievements in scientific research, are all based on scientific and technical literature.