naturalgas天然气naturaladj.自然的；天然的；私生的natural dentition[医] 天然牙列natural sanctuary自然古迹natural gas motor天然气发动机natural soil road天然土路natural advantage天助, 自然优势natural resonance固有谐振,自然共振,固有共振natural dialectic自然辩证法natural privilege天然特权natural phenomena自然现象natural oil stone天然油石