大都市一直是货币经济的所在地。
The metropolis has always been the seat of the money economy.
Drones in the future will be as ubiquitous as smartphones are today.
译文：金子遇火烧炼才能识别出成色如何，人与钱财打交道就能看出心地如何。赏析：金钱虽非万能，却能看清人心。钱，是感情的试金石，它能探出人性，看透人心。钱能看清一个人的真实面目，也最能看清自己在别人心中的分量。
任何一种成瘾都是恶习，无论是对酒精、吗啡或理想的成瘾。
数学的美只对那些更有耐心的追随者展示。
The true measure of success is impact, not just income.