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1. lever

   Bar that turns on a fixed point to lift things

2. fulcrum

   Point on which a lever turns

3. pulley

   Wheel with a rope used to lift loads

4. wedge

   Two slanted sides that split or cut things

5. screw

   Inclined plane wrapped around a post

6. inclined plane

   Flat slanted surface such as a ramp

7. wheel and axle

   Wheel joined to a rod that turns with it

8. load

   Object being moved by a machine

9. effort

   Force you use to make a machine work

10. work

    Using force to move something a distance

11. ramp

    Slope that makes lifting easier

12. gear

    Wheel with teeth that turns another wheel

13. compound machine

    Machine made of two or more simple machines

14. axle

    Rod at the center of a wheel

15. crowbar

    Lever used to pry things open

16. seesaw

    Playground lever with a fulcrum in the middle

17. thread

    Spiral ridge on a screw

18. force

    A push or a pull

19. friction

    Force that slows rubbing surfaces

20. machine

    Tool that makes work easier