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Hot air balloons are a good illustration of Charles' law... that gases expand when they're heated. A bicycle pump illustrates Boyle's law: if you put your finger over the end of a bike pump and push in the plunger, the gas pressure inside will increase, and you'll feel it trying to push your finger out of the way. Pressure of a gas increases with temperature, which is why you need to change the amount of air in your car tires when it gets very hot or very cold (Gay-Lussac's law), and blowing up a balloon involves Avogadro's law... the more gas molecules you blow into the balloon, the larger the volume becomes.
Just a few of many examples!