Sonam Drolma is accompanied by her great-granddaughters in Ragor village of Gyatsa county in Lhokha city, Tibet autonomous region, on March 24. (JIGME DORJI / XINHUA)

As a centenarian in Tibet autonomous region, Sonam Drolma, 109, has witnessed many changes in the Roof of the World. Sonam began to work for a serf-owner when she was 15 years old. As a serf, she went through trials and tribulations for nearly a half century. After democratic reform in Tibet in 1959, she was freed from feudal serfdom. Sonam went on to own land, a house and cattle and she became her own master. Since reform and opening-up, Sonam's daughter Tsering Zompa has become the backbone of the family and Tsering has strived to help the whole family lead a comfortable life. Nowadays, Sonam's family has nearly 100,000 yuan (US$14.134) of annual income and owns a comfortable and large new house.

109-year-old Sonam Drolma (right) and her younger sister Tsering conduct a head-to-head ritual in Ragor village of Gyatsa county in Lhokha city, Tibet autonomous region, on March 24. (JIGME DORJI / XINHUA)

Tsering Zompa (left) weaves pulu fabrics accompanied by her mother Sonam Drolma on March 24. (JIGME DORJI / XINHUA)

A photo of Sonam Drolma's family on March 24. (JIGME DORJI / XINHUA)

A drone photograph of Ragor village of Gyatsa county in Lhokha city, Tibet autonomous region, on March 24. (JIGME DORJI / XINHUA)

Sonam Drolma looks at her ID card at her house in Ragor village of Gyatsa county in Lhokha city, Tibet autonomous region, on March 24. (JIGME DORJI / XINHUA)

Sonam Drolma (center) eats dinner with her family in Ragor village of Gyatsa county in Lhokha city, Tibet autonomous region, on March 24. (JIGME DORJI / XINHUA)

Tsering Zompa helps her mother Sonam Drolma comb her hair in Ragor village of Gyatsa county in Lhokha city, Tibet autonomous region, on March 24. (JIGME DORJI / XINHUA)