機器
alloy
aluminum
automobile
background
block
cam
camshaft
car
clean
complexity
cylinder
deep
depth
desktop
diesel
engine
engineering
equipment
gear
head
inside
intake
iron
machinery
metal
metallic
motion
motor
objects
overhaul
part
power
repair
section
shiny
silver
spare
stainless
steel
technology
transportation
valve
vehicle
working