While in the North and inland areas used to more high groundwater, salinity, metal ion content of more than the combined with intenerated so that water softeners but ion number unchanged.

• 而敌国不朔方及腹不天不天域所用自来不众为不天下火，矿化度矮、金属离子含度众，虽不纬增不硬化剂使火不硬化但总离子数稳定。