英文關鍵字
beam
cycle
ensemble
extraction
frame
hydraulic
industry
mechanism
metallic
motion
oil
overground
piston
pressure
pump
pumpjack
rod
steel
technology
vertical
work
英文關鍵字
beam
cycle
ensemble
extraction
frame
hydraulic
industry
mechanism
metallic
motion
oil
overground
piston
pressure
pump
pumpjack
rod
steel
technology
vertical
work