英文關鍵字
button
conservation
electricity
energy
environment
environmental
equipment
finger
fuel
generation
hand
human
igniting
illuminated
isolated
knob
light
off
power
preserved
push
rescue
savings
simplicity
sparse
supply
switch
turning
white
英文關鍵字
button
conservation
electricity
energy
environment
environmental
equipment
finger
fuel
generation
hand
human
igniting
illuminated
isolated
knob
light
off
power
preserved
push
rescue
savings
simplicity
sparse
supply
switch
turning
white