英文關鍵字
acid
ammonia
chemical
chemistry
chimney
cloudy
co2
column
construction
cylindrical
danger
ecology
environment
factory
fertilizer
fuel
gas
gasoline
industrial
industry
manufacturing
many
metal
methanol
modern
nitric
nitrogen
obsolete
oil
petrochemical
petrol
pipes
plant
plumbing
poison
pollution
polypropylene
power
processing
production
refinery
sky
smoke
station
steam
tank
technology
tower
toxic
tube