Ibrahim Boubacar Keita was sworn in as Mali's new president after winning the country's first election since last year's coup. Mr.Keita vowed to protect the democratic gains and rebuild national unity during a small ceremony Wednesday in the capital Bamako. _________________________Oxfam says this form of tax evasion costs African governments more than 38 billion dollars per year. Jennifer Lazuta has details. 易卜拉欣`布巴卡`凯塔赢得自去年政变以来马里第一次全国大选胜利后宣誓就任总统.周三,在首都巴马科的小型庆典上,凯塔先生承诺将保护民主果实,重建统一的国家. _________________________施乐会称,这种逃税方式给非洲国家每年造成超过380亿美元的损失.詹尼佛`拉祖塔为您报道更多细节.