19
60
abstract
bolt
bulb
candle
concept
conservation
day
design
draw
earth
eco
electric
element
energy
environment
friendly
global
globe
graphic
hand
hour
icon
illustration
isolated
leaf
life
light
march
minute
off
power
protection
retro
saving
science
scissor
sign
symbol
technology
television
template
text
time
turn
vintage
world