earth's秘书的职责
earthn.地球;泥土;世间
earth inductor地磁感应器
earth's centre
earth depositsn.土堆
earth refining陶土精制
earth rock dam土石坝
earth fissures地裂缝
earthing fault接地故障
earth material土料
earth building[计] 地面阻碍物
earth rotation地球自转