Zhè zuò kuàngshān yǐjīng kāicǎi le wǔshí nián.
This mine has been in operation for fifty years.
Kuàngshān gōngrén de gōngzuò huánjìng shífēn jiānkǔ.
The working conditions for mine workers are very harsh.
Fèiqì de kuàngshān xūyào jìnxíng shēngtài xiūfù.
Abandoned mines need ecological restoration.
