social mobility的用法和樣例：
例句
- This expansion of education has not brought about a similar increase in social mobility.
教育的擴張並未在社會流動性方面引起相似的增長。 - These obstacles have indeed suppressed productivity, incomes and social mobility in the countryside, and contributed to the widening gap between town and country.
這一制度極大地抑制了農村的生產力，收入和社會流動性的發展，進一步擴大了城鄉差距。
