On a stone mountain in the far suburbs of Beijing, there is a group of migrant workers from the Northeast who are engaged in stone mining all year round. Lao Cao, Xiao Cao, Lao Yu Lao Zhang are among them.
Overview：On a stone mountain in the far suburbs of Beijing, there is a group of migrant workers from the Northeast who are engaged in stone mining all year round. Lao Cao, Xiao Cao, Lao Yu Lao Zhang are among them.
