3.parity of incomes between rural workers and those in industrial occupations.
业人和在业部门任职者的收入相。
4.20世纪开始于对称性研究,宇称守恒开创了研究对称破缺的新纪元。
20 century began from the research of symmetry,the discovery of nonconservation of parity starts epoch of research of breaking symmetry.
5.This paper retrospects briefly the history of the discovery of Parity Nonconservation, analyses some questions on the Lee-Yang's Argument, and also makes comments on it.