英文關鍵字
coal
wagon
line
symbol
electricity
fuel
power
electric
solar
panel
turbine
dam
plant
petrol
gas
linear
background
lined
nature
water
hazard
flame
biofuel
business
oil
technology
ecology
charge
nuclear
renewable
city
rig
derrick
icon
motion
graphic
animation
pictogram
hd
animated
item
sign
color