Historically, stone was used by sailors in the 1800s for ship ballast.在历史上, 石头在19世纪被水手用作船只的压舱物。

There was no extra ballast on the tractor.拖拉机上没有额外的配重块。

Serious academic ballast has been added to the team by the recruitment of Ian Kennedy.伊恩•肯尼迪的加盟为团队的学术力量增添了重要砝码。

These new vehicles are accurately ballasted and stable.这些新车配重精准而且平稳。