In fact, doctors proved the 4 minutes for the mile was the limit of human ability.

事实上医生证明四分钟跑一英里,是人类能力的极限。

哈佛公开课 - 幸福课课程节选

For decades, ever since the mile was timed, no one broke the four minute barrier.

数十年来，自从开始一英里跑计时以来，没有人突破四分钟界限。

哈佛公开课 - 幸福课课程节选