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Wednesday, September 23, 2020

In the text below some words are missing. Select appropriate words to fill the gaps.

Gunpowder, also referred to as ‘black powder’, was the only known chemical (1) ……………. until the mid-nineteenth century. It (2) ………………….. I potassium nitrate, or ‘saltpeter’, which is an oxidizer, and a (3) ……………….. of charcoal and Sulphur serves as fuel. There is an academic consensus that gunpowder was initially (4) …………………… in China as early as the ninth century. This led to its (5) ………………….. in fireworks and in gunpowder weapons.

(1) unique (2) combination (3) drastic (4) changing (5) invented (6) contains (7) explosive (8) use


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