- 问题详情:In1800,onlythreepercentoftheworld'spopulationlivedincities.Onlyonecity—Beijing—hadapopulationofoveramillion.Mostpeoplelivedinruralareas,andneversawacityintheirlives.In1900,justahundredyearslater,roughly150millionpeoplelivedincities,andthew...
- 8155