英文關鍵字
background
black
cave
cavern
coal
conditions
copper
copy
corridor
dark
dig
diminishing
dirty
employment
engineering
entrance
escape
extraction
geology
gold
gravel
historical
history
horror
illuminated
industrial
industry
inside
interior
labor
lamp
mine
miner
mineral
mining
obsolete
old
perspective
safety
shaft
solitude
soot
stone
subterranean
tunnel
tunneling
underground
wall
way
work