The drainage systems of urbanized area include the municipal drainage systems that consist of rain pipes and the hydrological drainage system that developed from the farmdrainage system.
The team went to work upgrading the farm’s buildings and drainage, and establishing an annual farm day for volunteers to perform other needed maintenance and upgrades.
这个团队开始升级农场的建筑和排水系统，并且设立年度的农场日以使志愿者完成其他的维护和升级。
3
Farm irrigation and drainage mechanical power and grain purchasing price index have negative correlation to grain production.