Change the words in capital letters so that they make sense in the text

But why doesn’t the trail itself EXPLOSION________________? The reason is that burning the powder releases ENERGETIC __________ and gases. While the trail is burning, these are easily released into the SURROUND _____________ air, but when the gunpowder is CONTAIN _________________ within the barrel the energy and gases cannot easily escape and build up until … boom! Firework canisters provide a SINGULARITY __________________ upward facing outlet to channel this EXPLOSION __________________ energy. The wick ignites the gunpowder and the energy takes the EASY _____________ exit from the canister LAUNCH _______________ the firework high into the sky. The FLAMMABLE _________________ then makes its way through the fireworks enin casing and the same REACT _______________ occurs high above our heads. So, while the CHINA _______________ alchemists never found the compound for eternal life they did find something that would go on to shape all of CIVIL _______________, something that has caused many tragic moments in human history and yet still gives us hope when we look up and CELEBRATE __________________ at the COLOR ________________ night sky.

Answers

Exercise 2:

Fireworks	A device that you set off on a holiday and it’ll produce colored lights, smoke and noise in the sky
Gunpowder	Highly explosive substance used in bombs, bullets and fireworks
To propel	To cause to move forward or upward
Flammable	Capable to burn rapidly
Trail	A trace or a mark left by a moving body
Canister	A metal or plastic container used for storage
Wick	A cord that is used in oil lamps or candles to draw up the fuel to the fire
To ignite	To set fire to something

Exercise 3.

a trail;

fireworks;

flammable;

gunpowder;

wick;

propels;

canisters;

ignited.

Transcript of the video

Everybody loves fireworks. The lights, the colors and, of course, the big boom. But the history of fireworks isn’t all hugs and celebrations. Long before epic fireworks displays, chemists in China invented the key ingredient that propels those bright lights into the sky. That invention was what we now call gunpowder. Our story begins back in ancient China in the mid-ninth century where early Chinese alchemists were trying to create a potion for immortality. Instead what they created was a flammable powder that burnt down many of their homes. They quickly realized that this black powder which they called fire medicine was precisely the opposite of something that would make you live forever. In these early days the Chinese hadn’t yet figured out how to make the powder explode. It was simply very flammable and their armies used it to make flaming arrows and even a flame thrower. But once they figured out the right proportions of ingredients to create a blast they began using the powder even more, creating fireworks to keep evil spirits away and bombs to defend themselves from Mongol invaders. It was these Mongols, most likely, who spread the invention of gunpowder across the world. After fielding Chinese attacks they learnt how to produce the powder themselves and brought it with them on their conquests in Persia and India.

William of Rubruck, a European ambassador to the Mongols, was likely responsible for bringing gunpowder back to Europe around 1254. From there engineers and military inventors created all kinds of destructive weapons from bombs to guns, to cannons. Gunpowder left its mark on the world in some pretty terrible ways in contrast to the beautiful marks they can leave in the air. So, how does black powder propel fireworks into the sky? You might have seen old westerns or cartoons where a trail of gunpowder is lited and it leads to a large and obviously explosive barrel. Once the fire gets to the barrel a large boom occurs. But why doesn’t the trail itself explode? The reason is that burning the powder releases energy and gases. While the trail is burning these are easily released into the surrounding air, but when the gunpowder is contained within the barrel the energy and gases cannot easily escape and build up until … boom! Firework canisters provide a single upward facing outlet to channel this explosive energy. The wick ignites the gunpowder and the energy takes the easiest exit from the canister launching the firework high into the sky. The flame then makes its way through the fireworks enin casing and the same reaction occurs high above our heads. So, while the Chinese alchemists never found the compound for eternal life they did find something that would go on to shape all of civilization;, something that has caused many tragic moments in human history and yet still gives us hope when we look up inand celebration at the colorful night sky.

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