translation.en: But we also know it's only through experiment that we'll discover exactly how to run a low carbon city, how to care for a much older population, how to deal with drug addiction and so on.
translation.zh: 但同时我们也知道只有通过实验 我们才会发现怎样运行一个低碳的城市， 怎样照料更大的老龄化人口， 怎样解决吸毒问题，等等。