Billionaire Bill Gates listens during a news conference with Carlos Slim, unseen, to announce donations to Mexico's International Maize and Wheat Improvement Center, known by its Spanish initials as CIMMYT, in Texcoco, Mexico, on Wednesday, Feb. 13, 2013. The group, which performs research for agricultural productivity, will open its research facility this week. Photographer: Susana Gonzalez/Bloomberg via Getty Images
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