機器
3d
alternative
aqua
architecture
barrage
building
care
cartoon
conserve
construction
dam
drop
droplet
ecology
electric
electricity
energy
environment
gauge
hydro
icon
industry
innovation
irrigation
isometric
manufacture
movement
nature
plug
power
pressure
purity
renewable
resource
river
saving
sign
steam
supply
symbol
technology
tides
transform
turbine
usability
water
wave