noun 下载 🔗分享 龙骨上桁,内龙骨。 A longitudinal beam fastened on top of the keel of a vessel for strength and stiffness. Examples : "The shipwright carefully bolted the thick keelson to the keel, adding vital strength to the wooden boat's structure. " 造船匠小心地将厚实的龙骨上桁用螺栓固定在龙骨上,为这艘木船的结构增加了至关重要的强度。 nautical structure vehicle 与AI对话词汇游戏阅读练习