noun🔗Share基础设施，下部结构，底层结构 The supporting part of a structure (either physical or organizational; the foundation)."The old house needed repairs because the substructure, the wooden frame beneath the floor, was rotting. "这栋老房子需要维修，因为它的下部结构，也就是地板下面的木制框架，已经腐烂了。structurearchitecturebuildingorganizationpartChat with AIVocabulary GamePractice Reading
noun🔗Share道碴, 路基. The earth or gravel that the railway tracks are embedded in."The train tracks felt stable because the construction crew had recently reinforced the substructure with fresh gravel. "火车轨道感觉很稳固，因为施工队最近用新的碎石加固了道碴/路基。materialgeologystructureChat with AIVocabulary GamePractice Reading
