Unit 13: Inventions

a handle you can use it to pull or push a machine work

• screw

• lever

• light bulb

• hammer

the glass part of an electric light that gives light

• doorknob

• lever

• light bulb

• wheel and axle

a path that you use instead of steps to go up or down

• wedge

• ramp

• stairs

• screw

a piece of wood or other material, with one thick and one thin pointed end

• wedge

• wheel and axle

• stairs

• screw

a type of machine that is made of a rope or chain that is wrapped around a bar that is attached to a wheel

• ramp

• wheel and axle

• hammer

• axe

a tool with a handle and a heavy metal part, which you use for hitting nails into things

• light bulb

• screw

• hammer

• axe

You walk on them to go up or down.

• lever

• axe

• wheel and axle

• stairs

You use it to cut down trees or chop wood.

• lever

• axe

• hammer

• wedge

a small metal thing with a sharp end, which you use for joining things together. You push it into something by turning it with a special tool.

• screw

• wheel and axle

• hammer

• wedge

You use it to open or close the door.

• screw

• axe

• hammer

• doorknob