A five-membered heterocyclic ring compound, C4H5N, having an odor similar to chloroform. It is the parent compound of hemoglobin, chlorophyll, and many other complex, biologically active substances.是什么意思_A five-membered heterocyclic ring compound, C4H5N, having an odor similar to chloroform. It is the parent compound of hemoglobin, chlorophyll, and many other complex, biologically active substances.在线翻译_英语_读音_用法_例句