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Mamoudou Gassama, a Malian migrant, won widespread praise after climbing the outside of the building to save a four-year-old boy hanging from a balcony in Paris. Now he is to be made a French citizen.Video showed him being cheered on by spectators as he pulled himself from balcony to balcony to the fourth floor.After meeting him at the Elysee Palace, President Emmanuel Macron said he would be made a naturalized citizen. He personally thanked Mr Gassama, gave him a medal for courage and said he would also be offered a position in the fire service.The heroic story unfolded on Saturday evening on函数的定义域是  　▲ 　 ．