英文關鍵字
cog
danger
drive
energy
engineering
finger
gear
gearing
grease
helical
hurt
industry
mechanical
noise
power
pressure
risk
safe
safety
showing
speed
spin
static
stationary
trap
vibration
wheel
work
working
英文關鍵字
cog
danger
drive
energy
engineering
finger
gear
gearing
grease
helical
hurt
industry
mechanical
noise
power
pressure
risk
safe
safety
showing
speed
spin
static
stationary
trap
vibration
wheel
work
working