Unlikely friendship highlights inequalities

At first glance, Weng Yongkai and Song Xiuru have little in common. Weng is sophisticated and cosmopolitan, an expert on rural healthcare with a PhD in molecular biology. Song is homespun, with barely an elementary school education, and has lived all her life in a small town in Shaanxi province.

But the two women are close friends, linked by years of shared experiences that reflect some of the changes, opportunities and inequities that have defined China's last 30 years.

In 1969, at the height of the "cultural revolution" (1966-76), Weng arrived in Jiziwan, a remote village in Shaanxi, to "learn from the peasants". It was a far cry from her native Beijing. Most residents lived in small, manmade caves carved in the loess mountains. There was often not enough food and water was scarce.