Carbazole, a kind of nitro heterocyclic compound, was the main constituted part of the coal tar fraction.There was about 15% of the carbazoles contained in the high temperature coal tar.是什么意思_Carbazole, a kind of nitro heterocyclic compound, was the main constituted part of the coal tar fraction.There was about 15% of the carbazoles contained in the high temperature coal tar.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句