translation.en: Mobility in developing world cities is a very peculiar challenge, because different from health or education or housing, it tends to get worse as societies become richer.
translation.zh: 在世界上发展中国家城市里 流动性是一个非常严峻的挑战 因为它和健康 教育或住房不同 当社会变得更富有时 它反而变得更糟