More than a hundred years ago the city offered a bounty to ships which would bring to the port rockballast instead of sand.
一百多年前，该城市对载运碎石而非泥土来港的船只提供奖赏。
2
The model test aimed to study hydraulic characteristics of buffer pit ballast discharge after rock clog in deep water was blasted.
试验对深水岩塞爆破后缓冲坑泄渣的水力特性进行了研究。
3
Even rock tools in use by heavy bump, not fresh out of stone ballast it up, but not as metal tools, as a result of deformation and destruction of accuracy.