4

U.S.S. Arizona Memorial at Pearl Harbor

4

Chip's Tips on Equatorial Guinea

2

Treeless Plains! Steppe

4

Maddy's North Carolina Diary

4

The Pygmy People

4

Tropical Rainforest

4

Famous Americans: Abraham Lincoln

2

Four Seasons! Deciduous Forest

4

Steppe

4

Kremlin, Russia

4

Mount Rushmore

4

Father's Road Trip

2

Warm Grasslands! Savanna

4

Montane Forest

4

Chip's Tips on United States

4

Maddy's Washington, D.C. Diary

4

Chip's Tips on Yemen

4

Famous Americans: Thomas Jefferson

3

Friction

4

Father's Road Trip

4

Washington Monument

4

Deciduous Forest

3

Mercury

4

Chip's Tips on Qatar

4

Savanna

3

Martin Luther King, Jr.

4

Taiga

4

Maddy's Missouri Diary

3

Venus

3

All About History