2 ตัวล่าง 7 งวดยังไม่ผิด ตามต่อ งวด 1 ก ค.2562
An account of a visit to the ancient historic silver mine in Potosi Bolivia. The article outlines the features of tours that visitors can take to the mines, as well as indicating the harsh conditions suffered by the miners in the town.
from: http://ezinearticles.com/?Potosi-Silver-Mine---Bolivian-Health-and-Safety&id=5366932

