2025-07-30 16:18:48 浏览次

ballast是什么意思 英[ˈbæləst] 美[ˈbæləst] n. 压载物, 压舱物[经] 底货, 压舱货n. any heavy material used to stabilize a ship or airshipn. coarse gravel laid to form a bed for streets and...