The Earth's water

How much of the Earth's surface is water?

• 50%

• 60%

• 70%

• 90%

Which bodies of water are formed of salt water?

• Oceans and seas

• Oceans and glaciers

• Lakes and rivers

• Glaciers and aquifers

What is a river?

• An enormous area of salt water.

• A large body of water surrounded by land.

• A thick mass of ice.

• A flowing stream of fresh water.

What is a large body of water surrounded by land on all sides?

What is formed when water filters the ground and collects between layers of rock?

• Glacier

• River

• Lake

• Aquifer

Draw an aquifer.

What is formed when groundwater flows naturally to the surface?

• A glacier.

• A well.

• A spring.

• A cloud.

We find three stages in a river:

• Upper, medium and low course.

• Source, medium and lower course.

• Top, middle and mouth course.

• Upper, middle and lower course.

The upper course is the beginning of a river and water flows quickly.

• True

• False

During the middle course, water begins to slow down but it is smaller than in the upper course.

• True

• False