ballast
柯林斯词典
1. N-UNCOUNT Ballast is any substance that is used in ships or hot-air balloons to make them heavier and more stable. Ballast usually consists of water, sand, or iron. 压舱物
返回 ballast
1. N-UNCOUNT Ballast is any substance that is used in ships or hot-air balloons to make them heavier and more stable. Ballast usually consists of water, sand, or iron. 压舱物