He later heard that the teacher had another 2-year-old child at home tied up with a rope to keep him from running away, so that she could get on with teaching.

Although China had enacted the compulsory education law the year before to guarantee nine years' compulsory and free basic education, poverty held some rural students back.

And some rural teachers, either because they were so poor or because they watched enviously as other people built new houses, opted to become migrant workers in cities so they could earn more money.

"There would be no hope if there were no teachers," Xie says.

For both Wang and Xie documentary photography is always a work in progress.