It analyzes the relation of authentication center, merchant and client, discusses the defrayment problem of E-commerce and puts forward a better scheme.

分析了一个电子商务系统中认证中心，商家，客户三个实体的关系，研究了电子商务的支付问题并提出改进方案。

As the Nanjing tap-water outreaching, the government controlled the cholera and economized a great sum of defrayment every year, and let the Nanjing fire fighting system to be more perfectly.

同时，随著自来水管线与救火龙头的装设，南京的消防系统亦更趋完善。