Water and rivers

What percentage (%) of salt water is there in the world?

__%

What percentage (%) of fresh water is there in the world?

__%

Only about __ of Earth's fresh water is accesible to humans.

• 69 %

• 1 %

• 30 %

• 3 %

Waves are produced by...

• the effect of the wind

• the effect of the Moon (gravity)

• Changes in temperature

The rise (up) or fall (down) of water level in the oceans.

• Tides

• Currents

• Waves

Tides are produced by...

• the effect of the wind

• the effect of the Moon (gravity)

• Changes in temperature

Currents are produced by...

• the effect of the wind

• the effect of the Moon (gravity)

• Changes in temperature

In oceans and seas, we find _____ water.

In lakes and rivers, we find _____ water.

A _________ is a small river that ends in a bigger river.