Unit 7. Machines and inventions

A plane is ...

• A simple machine

• A complex machine

A wheel is a ....

• simple machine

• complex machine

A pulley has a wheel and an axle. A rope goes around the outside of the wheel. The pulley is a....

• simple machine

• complex machine

A sharpener uses...

• burn fuels

• human energy

• sun, wind and water energy

• electricity

A plane uses...

• burn fuels

• human energy

• sun, wind or water energy

• electricity

Nowadays, some machines use energy from the sun, wind or water. They produce very little pollution.

• True

• False

A computer is a ...

• complex machine

• simple machine

The CPU (central processing unit)

• processes data and organises how all the other parts work.

• is where we read texts and see photos, pictures and videos.

• allows us to type texts and give commands

• moves the cursor on the screen and we use it to click on texts and pictures.

The screen

• processes data and organises how all the other parts work.

• is where we read texts and see photos, pictures and videos.

• allows us to type texts and give commands

• moves the cursor on the screen and we use it to click on texts and pictures.

The keyboard

• processes data and organises how all the other parts work.

• is where we read texts and see photos, pictures and videos.

• allows us to type texts and give commands

• moves the cursor on the screen and we use it to click on texts and pictures.