Any of various explosive powders used to propel projectiles from guns, especially a black mixture of potassium nitrate, charcoal, and sulfur.是什么意思_Any of various explosive powders used to propel projectiles from guns, especially a black mixture of potassium nitrate, charcoal, and sulfur.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句