noun🔗Share龙骨上桁，内龙骨。 A longitudinal beam fastened on top of the keel of a vessel for strength and stiffness."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。nauticalstructurevehicleChat with AIVocabulary GamePractice Reading
