機器
bacterium
bath
black
bulldozer
business
coal
commercial
control
crane
ecology
equipment
faucet
filter
flask
garbage
icon
industry
liquid
microscope
pictogram
pipe
pipette
process
processing
purification
quality
recycling
refuse
rubbish
sewage
sewer
sewerage
shovel
sign
sink
stump
symbol
technology
toilet
tractor
trash
treatment
truck
waste
water
weed
wood
working