natural air自然空气naturaladj.自然的；天然的；私生的natural and low-enriched uranium天然铀和低浓缩铀natural smoking ventilation system自然排烟系统natural evergreen broadleaf forest天然常绿阔叶林Natural vibration period of bridge桥梁自振周期natural mineral water for drinking饮用天然矿泉水Naturalization of Marxism in China马克思主义中国化natural brown kraft wrapping paper本色牛皮包装纸natural gamma ray spectrum logging自然伽马能谱测井natural gamma ray spectrometry log自然伽马能谱测井Natural-ecological sensitiveness自然-生态敏感性