词汇	chemical precursor
释义	chemical precursor 化学前体
随便看	horizontal rectangular channel horizontal redundance check horizontal redundancy check horizontal redundancy checking horizontal reel horizontal reference Horizontal Reference Line horizontal reference plane horizontal reference point horizontal refinement horizontal reflection horizontal reflector horizontal refraction horizontal refraction error horizontal refractor horizontal refreshment horizontal refreshments horizontal refresh rate horizontal refrigerated display cabinet horizontal regenerator horizontal registration control horizontal regression horizontal reinforcement horizontal reinforcing bar cutting machine horizontal relation of jaws