translation.en: But I think the most important one is that London was this city of 2.5 million people, and it was the largest city on the face of the planet at that point.
translation.zh: 但是我认为最重要的一个原因是 伦敦是个拥有两百五十万人口的城市， 它是那时候这个星球上最大的一个城市。