A bigger concern is that early selection fails children from poor and immigrant families, who are likeliest to attend the least academic schools and to miss out on apprenticeships.
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。
3
Neural network have the abilities of self-learning, adapt and parallel management, but the structural selection lacks academic bases.