4

Chip's Tips on Equatorial Guinea

4

U.S.S. Arizona Memorial at Pearl Harbor

4

Taiga

3

Mars

4

Father's Road Trip

4

Famous Americans: Thomas Jefferson

4

Famous Americans: Abraham Lincoln

4

Mount Rushmore

4

Chip's Tips on Yemen

4

Steppe

3

Mercury

4

Forbidden City, China

4

Father's Road Trip

4

Kremlin, Russia

2

Four Seasons! Deciduous Forest

3

Friction

4

Maddy's North Carolina Diary

4

Deciduous Forest

3

All About History

3

Venus

4

Montane Forest

2

Treeless Plains! Steppe

4

Chip's Tips on Qatar

4

Chip's Tips on Oman

4

Tropical Rainforest

4

The Pygmy People

4

Maddy's Missouri Diary

3

Martin Luther King, Jr.

4

Washington Monument

4

Savanna