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来源：雅诚德英语网
By the 6th century BC, athletes began to specialize in particular sports, and even began to hire coaches.
到了公元前6世纪，运动员开始专攻个别项目，甚至开始雇佣教练。
By the 6th century BC, athletes began to specialize in particular sports, and even began to hire coaches.
到了公元前6世纪，运动员开始专攻个别项目，甚至开始雇佣教练。