Earth's Changes

What can cause erosion?

• dirt and water

• sand and wind

• water and sand

• wind and water

How can wind erosion hurt a farmer's crops?

• Wind can blow away the top layer of soil

• Wind can blow away seeds

• Wind can change the shape of sand

• Wind can change the shape of rocks

Why do floods happen?

• It's so windy that rivers overflow

• It rains so much that rivers and lakes overflow

• It's sunny for a lot of days in a row

How can we control water and wind?

• Build homes close to the ocean

• Plant a row of trees next to the crops

• Plant crops right by the river

• Build walls around rivers so they don't overflow

How much of Earth is covered with water?

• two thirds

• three fourths

• one half

• one third

Can erosion change the way Earth looks?

• yes

• no

How was the Grand Canyon formed?

• Ocean waves changed the land

• Wind changed the land

• Mississippi River formed it

• Colorado River formed it