英文關鍵字
arm
beam
bridle
cable
counterweight
cycle
electrical
engine
equipment
extraction
field
frame
hydraulic
industry
metallic
motion
new
oil
overground
piston
pressure
pump
pumping
pumpjack
rotational
steel
surface
vertical
well
yield
英文關鍵字
arm
beam
bridle
cable
counterweight
cycle
electrical
engine
equipment
extraction
field
frame
hydraulic
industry
metallic
motion
new
oil
overground
piston
pressure
pump
pumping
pumpjack
rotational
steel
surface
vertical
well
yield