free-draining molecule

例句：

1. 1. The new drainage system isdesigned to free-drain the areaeffectively.
   新的排水系统设计用来有效地自由排水。
2. 2. The road was free-draining, allowing vehicles to pass quickly.
   这条道路是自由排水的，车辆可以快速通过。
3. 3. Theconstruction of this bridge was designedto be free-drainingto prevent flooding during heavy rains.
   这座桥梁的建设被设计成自由排水，以防止大雨时发生洪水。