Nitrogen Heat Exchange氮热交换器 Normal Hydrogen Electrode标准氢电极 Sodium Hydrogen Exchanger钠氢器 National Housing Endowment全国房屋养老 No Happy Ending不快乐的结局 Normalized Hydrogen Electrode归一化氢焊条 Nelson Hill Electronics纳尔逊·希尔电子学 Nuclear Hypersensitive Element核敏感元件