3

Christopher Columbus

3

Space Exploration

4

Maddy's Washington Diary

4

Maddy's Idaho Diary

4

Maddy's Alaska Diary

4

Maddy's Washington, D.C. Diary

4

Maddy's Oregon Diary

4

Chip's Tips on United States

3

Straits of the World

4

Maddy's Montana Diary

3

Cinco de Mayo

4

Chip's Tips on Canada

4

Maddy's South Carolina Diary

4

Amphibians

3

Fjords of the World

3

Neil Armstrong