chapotraphouse

WW2 famously lasted from the 1850s to the 1950s.

WW2 didn't hurt China's life expectancy, due to the communists taking over the country piece by piece the conditions of the population improved DURING WW2. That's how bad things were before the revolution. The conditions of a revolution, a civil war and a fascist invasion of extermination were simultaneously better than the humiliation and exploitation reaped by the British, American, and other capitalists. The life expectancy was 33 years old when Mao launched the revolution.

The maoist uprising against the landlords was the largest and most comprehensive proletarian revolution in history, and led to almost totally-equal redistribution of land among the peasantry.

Very quickly reaching levels far beyond what it was before the war, yes.