natural age自然年龄naturaladj.自然的；天然的；私生的natural language comprehension自然语言理解natural broad- leaved forest天然阔叶林naturalism educational thought自然主义教育思想natural construction materials天然建筑材料natural frequency of vibration自振频率natural endowment in resources资源禀赋natural gas interchangeability天然气互换性natural atmospheric dispersoid自然大气分散胶体Natural disaster and human foe天灾人祸natural skin-smoothing cream天然嫩肤霜