英文關鍵字
airtight
background
blowtorch
copper
danger
element
energy
engineer
engineering
equipment
factory
flame
gas
hand
heat
heating
hermetic
industrial
industry
isolated
looking
machine
machinery
maintenance
man
manufacturing
mechanical
metal
obscure
operator
pipe
pipes
power
pressure
repairman
safety
skilled
solder
soldering
technician
technology
tight
tool
torch
welding
work
worker
workers
working