translation.en: But if, and only if, [the poorest] get out of poverty, they get education, they get improved child survival, they can buy a bicycle and a cell phone and come [to live] here, then population growth will stop in 2050.
translation.zh: 但是如果，只有如果 他们能脱离贫穷， 他们能受教育，能提高儿童成活率， 他们才能买自行车，手机，他们会移动到这儿来， 然后人口增长 会在2050停止。