參考答案:

Gunpowder was the first chemical explosive and propellant. Prior to the invention of gunpowder, many incendiary bombs and burning devices had been used. The invention of gunpowder is usually attributed to Chinese alchemy. It is known to all that gunpowder is listed as one of the “Four Great Inventions” of China. The invention was made perhaps as early as in the Tang Dynasty.Knowledge of gunpowder was spread throughout the world as a result of the Mongol conquests in the 13th century. It was employed in warfare to some effect from at least the 14th century.

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