A simple machine in my life—door
2019-03-22 本文已影响0人
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Doorknob
A wheel and axle is a simple machine.
It makes work much easier.
A doorknob is a wheel and axle.
The doorknob makes it easier to open the door.
Doorknob
Doorknob
Doorknob
A wheel and axle is a simple machine.
It makes work much easier.
A doorknob is a wheel and axle.
The doorknob makes it easier to open the door.
