Queen Elizabeth's 90th birthday celebration

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Britain's Queen Elizabeth, the world's longest-serving monarch, turns 90. Credit: Reuters

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Britain's Queen Elizabeth, the world's longest-serving monarch, turns 90. Credit: Reuters

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Britain's Queen Elizabeth, the world's longest-serving monarch, turns 90. Credit: Reuters

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Britain's Queen Elizabeth, the world's longest-serving monarch, turns 90. Credit: Reuters

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Britain's Queen Elizabeth, the world's longest-serving monarch, turns 90. Credit: Reuters

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