At age 12, Djokovic moved to Germany, where he spent four years training with Nikola Pilic.

12岁时，德约科维奇移居德国，在那里他花了四年时间与尼古拉·皮利一起训练。

" These boys have been training all year, " remarked the man.

“这些男孩一整年都在训练，”男人说。

Eight billion dollars worth of training a year, according to studies from the " Harvard Business Review." These same studies also conclude that these trainings don't work and often backfire.

的研究，每年价值 80 亿美元的培训。 根据“哈佛商业评论”这些相同的研究还得出结论， 这些培训不起作用并且经常适得其反。