But he also took it for granted that division of labor is itself responsible for economic growth and development and it accounts for the difference between expanding economies and those that stand still.

【参考答案】

但是他想当然地认为劳动分工本身就可以促进经济增长和发展，并且以此来解释为什么有些经济体经济快速增长，而有些则停滞不前。