英文關鍵字
animation
ball
bearing
engine
explosive
globe
loop
machine
manufacturing
mechanic
mechanism
metal
part
roller
rolling
rotate
sphere
steel
tellurion
terrestrial
the
wheel
英文關鍵字
animation
ball
bearing
engine
explosive
globe
loop
machine
manufacturing
mechanic
mechanism
metal
part
roller
rolling
rotate
sphere
steel
tellurion
terrestrial
the
wheel