英文關鍵字
bulldozer
catepillar
caterpillar
cleaning
construction
engine
heavy
machinery
macine
metal
motion
noise
object
road
scraper
snow
street
technology
tractor
winter
working
英文關鍵字
bulldozer
catepillar
caterpillar
cleaning
construction
engine
heavy
machinery
macine
metal
motion
noise
object
road
scraper
snow
street
technology
tractor
winter
working