HSK 5
Kuàngshān gōngrén de gōngzuò huánjìng shífēn jiānkǔ.
The working conditions for mine workers are very harsh.
HSK 7-9
Zhè zuò kuàngshān yǐjīng kāicǎi le wǔshí nián.
This mine has been in operation for fifty years.
HSK 7-9
Fèiqì de kuàngshān xūyào jìnxíng shēngtài xiūfù.
Abandoned mines need ecological restoration.
