We secretly go to Shangxi even pretend as labor many times and finally learn that Shangxi linfen city and yongji city are place with a lot of illegal coal mines.

• 我们不顾自身的安危，多次潜入当地，甚至扮成打工者进行卧底，终于了解到山西省临汾市、永济市是窑场比较集中的地方。