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Many inventions were created by accident.The inventors were trying to make something completely different.Here is one example.

Name of the inventor:Percy LeBaron Spencer Nationality:American Invention:The microwave Year:1945 How he invented it: .He was working on a machine to produce powerful radio waves（无线电波）. While standing next to the new machine,he noticed that a bar of chocolate in his pocket became soft. •He realized that the machine was able to cook things. .The first microwave weighed around 350 kilograms and was as big as a fridge.

（1）Where does Percy LeBaron Spencer come from?
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（2）When was the microwave invented?
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（3）What was the microwave used for?
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（4）Was the first microwave small or big?
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