_____ are walls built perpendicular to the shoreline in an attempt to stabilize the beach and keep sand from moving. (These walls are not built to protect a harbor entrance.)

Meandering rivers make bad state boundary lines because they are constantly shifting their location. In time, a meander bend may be cut off and form a crescent-shaped _____ lake. 

The Continental Divide _____.

The proposed Keystone XL Pipeline would bring oil from the _____ to the Gulf Coast.

Dust storms can cause all of these environmental problems EXCEPT _____.

Geologists have used radiometric dating to determine that the earth is ____ years old

Meandering rivers make bad state boundary lines because they are constantly shifting their location. In time, a meander bend may be cut off and form a crescent-shaped _____ lake. 

The proposed Keystone XL Pipeline would bring oil from the _____ to the Gulf Coast.

Hurricane Katrina created deadly flooding in New Orleans, Louisiana for all of these reasons EXCEPT _____

When using the scientific method, an idea that has been well tested and is widely accepted to be true is called a(n) _____.