Bolt is an exciting showman and, clearly, a gifted runner, but is he an inimitable oddity, or proof that athletes are simply getting faster overall?

• 博尔特是一个热情的主持人，显然他同时是一个天生跑步选手，他也是一个难以模仿的怪人，或者可以证明运动员只需跑的更快即可？